Log Message:
Update firefox36 to 3.6.27.

pkgsrc changes:
* use own mozilla-common.mk, some dependency differ from recent Firefox.
* switch to use system cairo.

Fixed in Firefox 3.6.27
* MFSA 2012-11 libpng integer overflow
Fixed in Firefox 3.6.26
* MFSA 2012-08 Crash with malformed embedded XSLT stylesheets
* MFSA 2012-07 Potential Memory Corruption When Decoding Ogg Vorbis files
* MFSA 2012-04 Child nodes from nsDOMAttribute still accessible after removal of \ 
nodes
* MFSA 2012-02 Overly permissive IPv6 literal syntax
* MFSA 2012-01 Miscellaneous memory safety hazards (rv:10.0/ rv:1.9.2.26)
Fixed in Firefox 3.6.25
* MFSA 2011-59 .jar not treated as executable in Firefox 3.6 on Mac