Tabs above document file browser header in tab bar

Integrate visually file manager header in tab bar when tabs above document
option in on. If tabs above document are off then use default gradient L&F.

Bottom divider for file browser header view is not integrated in header for
easier control if it is shown or not.
Simplify constraints used to layout document window

We now do the core layout with priorities that allow optional elements to insert themselves between existing elements.
Add left/right padding properties to OakTabBarStyle
Refactor
Use different tab background/divider images on 10.10
Add contentFrame property to OakTabItemView

This should return the content excluding borders and is used to create an image when dragging tabs. Long-term we probably should create a special drag image rather than ask the tab to draw itself.
Add thin close button image
Use thin close button images on 10.10
Read mate options from the MATEFLAGS environment variable

This is useful for users who want to permanently set things like --[no-]recent and --[no-]escapes.
Set MATEFLAGS to ‘--no-recent’ for TextMate commands

This way commands that open files via TM_MATE will not fill up the Open Recent menu.
Do not prevent empty lines from being a fold start/stop marker

This is compatible with how TextMate 1.x works. We identify empty lines because we want to ignore them when finding the last line in an indented block, though this commit should not break that, unless the language in question have one of the folding patterns match empty lines and have also enabled indent based foldings.
Ensure we create signature before uploading file

This is so that we do not upload anything if signature creation fails.
Checkin release notes
Account for tar potentially failing
Titlecase does not preserve case when everything is uppercase
Do not set default settings for Makefile (only source.makefile)

The problem is that if the user changes default settings then these are recorded for the current scope, which has lower precedence than settings set for a glob, so it was effectively impossible for the user to change soft tabs settings for Makefiles (without editing a .tm_properties file).

Also removed the ‘*.ninja’ glob for the same reason.