Process inline attachments in thread entry and support inline images in
piped emails

Support inline images across the system, with draft support

Migrate to a single attachment table
    That way we don't need a new table for everything we need to attach an
    inline image to (like a signature, for instance)

Add richtext support for internal notes

Implement images on site pages

* Image paste in Redactor
* Make non-local images optional
* Placeholder for non-local images
* Fix local image download hover
* Don't re-attach inline images

This is one of the last major hurdles to make osTicket fully translatable.
With the advent of 1.7.0, database migration is based on the MD5 hash of the
install SQL file. Therefore, the install SQL script cannot be modified (ie.
translated) or else the system cannot be migrated, since the MD5 hash will
no longer match up.

This patch pulls initial data out of the install file so that it can be
translatable. Eventually the install worksheet can allow a drop-down box of
the default system language. The default data from that language will be
loaded into the system.

Allow `streams.cfg` to be implied as 'core', which will default to only
upgrading the core osTicket stream.

Use signature to describe snapshots rather than md5

This patch allows the upgrader to upgrade multiple database update
'streams'. The main stream is renamed to 'core' to reflect changes made
to the config class. This will significantly ease customizations
requiring database customizations, and will make plugins requiring
database changes possible.

- timezone_offset was dropped from the config table at 1.7-dpr1
- upgrader: only apply five patches in one request
- upgrader: fix readPatchInfo to work correctly
- session: support migrating from 1.6 (again)
- config: support migrating from 1.6 (fallback)
- config: no default for 'isonline' setting
- config: fix SQL whitespace issue for schema signature fallbacks
- config: hash 1.6 versions in the schema signature lookup
- upgrader: fix logging bug in attachment migration

Change the config table from a column-based table to a key-value table
with namespacing. This allows several parts of osTicket to store their
respective configurations in the same table without requiring database
structure updates

'namespace' is reserved in PHP

Since the first department id cannot be assumed

Drop required usage of MyISAM tables, and drop fulltext indexes as they
are not used in the code currently anyway. Also, use a blob to store
session data so as not to waste space with UTF-8 encoding. Lastly, fix
session_id storage to use VARCHAR(255) which is required for versions
of MySQL < 5.0.3, and use ascii for the storage model for the
session_id as it will contain simple characters only.

The problem stems from assumed MySQL insert ids. In MySQL clusters, the id
numbers will not necessarily be consecutive. This patch causes the install
and upgrade patches to lookup the assumed values for the linked id numbers.

Remove piping setting option - it's now part of ticket create service (which include XML & JSON)

Make collation consistent - utf8_general_ci.

 Template is used for canned auto-reply - triggered by filters.

This will remove the upper limit of BLOB sizes imposed by MySQL with the
max_allowed_packet setting completely.

This adds a new table %file_chunk which will contain the filedata in smaller
chunks (256kB). It also includes a new class, AttachmentChunkedData, which
will handle reading and writing the data, abstracting away the chunks.

This is done by migrating data from the %file table to the %file_chunk
table. One must beware that this must safely (the migration that is) plug
into the both the live osTicket developers as well as the users doing a full
upgrade from osTicket-1.6*. For this, the AttachmentFile::save method was
patched to use the new AttachmentChunkedData class to write the attachment
data to the database in chunks. That is, the migrater will use the new code
on the major upgrade and bypass the filedata column of the %file table
altogether. Therefore, the patch associated with this commit will not
migrate any data for the major upgrade.

For developers doing incremental upgrades, the patch included in this
commit will transfer the data from the %file data to the new %file_chunk
table by chunking it. As written, only the first 16MB of the attachment is
migrated. This could easily be adjusted, but it seems like a reasonable
limit for now.

Force target selection on filter form
Add minor code improvements

* Change table name from ost_email_filter* to ost_filter*
* Add patch for target field.

And rearrange files to work with the new layout for the finalized upgrader

Allow staff members the ability to select a default paper size which will be
used in printing tickets via PDF. In the future, this may be overridden per
ticket by a dialog box at print time.