Fix class parameter not being evaluated.  Code was checking against [DTImageTextAttachment class].
Added missing check for nil value sent to enumeration block.
Merge pull request #452 from leehericks/lh_textAttachmentsWithPredicateFix

Fix class parameter not being evaluated.  Code was checking against [DTI...
Bypass font enumeration if a DTCoreTextFontOverrides.plist file is provided

This fixes a performance issue. Retrieving all the system fonts is quite
slow; and although this is done on a background thread, the parsing will
block until the overrides table is built.

So, if a DTCoreTextFontOverrides.plist is found, consider it canonical
and don't build the overrides table dynamically.
Update attributes property documentation.  Couldn't find where my custom attribute name got lowercased but it fits W3C recommendations and people should know if they use a camelcase name, it will be changed.
Added unit test for fallback font family
grouped font tests
implemented fallback font family
Merge pull request #467 from leehericks/lh_attachmentdocs

DTTextAttachment attributes property documentation
Merge pull request #459 from kemenaran/font-enumeration-override

Bypass font enumeration if a DTCoreTextFontOverrides.plist file is provided
current test update
Merge branch 'od/issue_471' into develop
Update DTFoundation to 1.4.2
implemented weak ref support (if deployment target allows it) #311
Merge branch 'od/issue_311' into develop
Removed DT_ADD_FONT_ON_ATTACHMENTS, there should always be a font added, even for attachments. #463
Updated isTrailing to work correctly for RTL
do not subtract trailing whitespace width for RTL text.
Change glyph run building to use first glyph position as offset. Fixes #444
Test HTML for #444