The installer assumes that the CWD of the running PHP process is setup/,
which isn't necessarily true (if run from a cli module, for instance).

- 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

The installer compares the md5 of the on-disk sql install file with the
signature file shipped alongside. If the signatures do not match, it will
refuse to install osTicket. On Windows(TM) platforms, PHP will automatically
translate newlines to Windows newlines (CRLF), which will corrupt the MD5
hash of the file.

This patch opens the file in binary mode explicitly to prevent the automatic
conversion.

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