Update system identifier in DOCTYPE of MathML-including exported XHTML.
From Josh Hieronymous.

(cherry picked from commit 4f0c81937537ca3bf92097e266d367290d6419a9)
Trivial fix: escape ampersands in file names before pushing to tab header (#8757)
Quick workaround for detection of Qt/Mac using pkg-config
Add Josh Hieronymous.
Fix logic error that led to bug #8777. I have no idea what I was
previously thinking.
Fix encoding problems in citation labels by using docstring (not string) where appropriate
Bug in 'Use non-tex fonts' checkbox auto-toggling (#8717)
pkg-config is not usable with self made Qt libs
add frameworks to linker flags for Mac OS X
Adding wrap-around pop-up question to simple find and replace dialog (fixing enhancement request #1262).
Establish missing connections to change_adaptor
Fix setting of is_child runparam if grandchildren are involved
de.po
Merge branch 'master' of git://git.lyx.org/lyx

# By Juergen Spitzmueller (6) and others
# Via Juergen Spitzmueller
* 'master' of git://git.lyx.org/lyx:
  de.po
  Fix setting of is_child runparam if grandchildren are involved
  Establish missing connections to change_adaptor
  Adding wrap-around pop-up question to simple find and replace dialog (fixing enhancement request #1262).
  add frameworks to linker flags for Mac OS X
  pkg-config is not usable with self made Qt libs
  Bug in 'Use non-tex fonts' checkbox auto-toggling (#8717)
  Fix encoding problems in citation labels by using docstring (not string) where appropriate
  Fix logic error that led to bug #8777. I have no idea what I was previously thinking.
  Add Josh Hieronymous.
  Quick workaround for detection of Qt/Mac using pkg-config
  Trivial fix: escape ampersands in file names before pushing to tab header (#8757)
  Update system identifier in DOCTYPE of MathML-including exported XHTML. From Josh Hieronymous.