zc.buildout >= 1.6.0-dev-SlapOS-013 automatically rebuilds parts whose referring parts are modified.

also revert "revert libXrender version because building cairo-1.10.2 failed."
also cleanup PKG_CONFIG_PATH.
also cleanup boost-lib recipe.

* add lzma support
* add xml support
* rsvg conversion is provided by rsvg-convert instead of librsvg
* specify ghostscript fonts directory

When compiling Mioga, one must still compile DBD::Pg one more time at the end.

Perl module Image::Magick and other, simple ones;
Patch for perl, creating a stable symlink to libperl.a.

(cherry picked from commit c060818b385d8af429725fb9c53fdb8068ad21d5)

6.7.6-7 fixes issue of darkening some images.
(cherry picked from commit 62885346a1b66d7d7d94b682c37316ad0b622a6a)

The librsvg contains rsvg-convert, the command used by imagemagic
to convert svg to png.

This reverts commit 1ea46ea8.

Don't use squash because in this way we will lost the history.