Unset $db in DboSource::read().

After calling $db->queryAssociatin(), it is necessary to unset db. 
This reverts commit 52d425737af584d33352ff0540dbf769006d82f5.
Fixes baked postLink()s
Merge pull request #3483 from dereuromark/master-hotfix-bake

Fixes baked postLink()s
Remove x bit on files.

PHP files should not have executable permission set.
Merge pull request #3481 from okinaka/master

Unset $db in DboSource::read().
Hotfix for older baked templates regarding postLink()
Merge pull request #3484 from dereuromark/master-hotfix-bake

Hotfix for older baked templates regarding postLink()
Fix issues where emails would have multipart/mixed when they should not.

When sending multi-part emails with no attachments we shouldn't include
the outer multipart/mixed header as it confuses Outlook and causes it to
show the email as having attachments even though there are none.

A bunch of tests need to be adjusted as the empty multipart/mixed
container has been removed.

Fixes #3474
Updated the test suite dispatcher to allow use of PHPUnit from Composer

Closes #3479
Fix test I forgot to fix in b8fa7ce1349e48047539a83f574c3ff87849cafa
fixes failing test cases in ModelTaskTest if not run in test-suite

Tests 'testSkipTablesAndAll' and 'testExecuteIntoAll' didn't took fixture
table 'core.number_tree' into account.
Merge pull request #3489 from rchavik/2.5-composer

Updated the test suite dispatcher to allow use of PHPUnit from Composer
Merge pull request #3493 from Schlaefer/fix-failingModelTaskTest

fixes failing test cases in ModelTaskTest if not run in test-suite
Fix inline attachments being broken when only sending an HTML text body.

The rel boundary was closed too early causing inline images to be
incorrectly included in the email message.

Refs #3474
Removed the little doc that lied

View::get() never looked up blocks
Merge pull request #3497 from jameswatts/feature/view-wat

Removed the little doc that lied
Make sure invalid arrays return empty array instead of throwing notices.
Merge pull request #3498 from dereuromark/master-hotfix-hash

Make sure invalid arrays return empty array instead of throwing notices.
Make help clearer around how to use UpgradeShell.

Closes #3504
Update version number to 2.5.1