gtk+ 3.10.2

https://mail.gnome.org/archives/ftp-release-list/2013-October/msg00097.html

Closes #23329.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
serf: make sure compiler choice is respected
libvpx: fix checksum.

Closes #23297.

Signed-off-by: Xiyue Deng <manphiz@gmail.com>
sonar 3.7.2

Closes #23341.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
grails 2.3.1

Closes #23344.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>
serf: fix universal build

Fixes #23342.
Add OS.mac? and OS.linux?
Rename MacOS to OS::Mac
Move MacOS modules under OS::Mac namespace

Closes #23138.
Merge XQuartz and X11 modules
Make condition clearer using names
Extract repeated conditional to a method
Improve superenv add/remove message.

* Now it includes all flags that are added or removed by superenv when
  passing "--verbose" or envvar VERBOSE or HOMEBREW_VERBOSE is set.