Merge pull request #940 from Arantor/release-2.1

! Typo in installer, causing categories table not to be made. Fixes #939...
Merge pull request #942 from Arantor/release-2.1

! Would have been nice if people had given me the error message, would h...
! Don't allow $boarddir, $sourcedir and $settings['theme_dir'] as attachment directories. Partial fix for #899

Signed-off-by: Michael Eshom <oldiesmann@oldiesmann.us>
Merge pull request #943 from Oldiesmann/release-2.1

! Don't allow $boarddir, $sourcedir and $settings['theme_dir'] as attachment directories
Merge pull request #945 from Arantor/release-2.1

! The beginnings of the new alerts system.