Multiple bugfixes and improvements after building gtk+ from scratch.

- Fix a bug in unzip-extraction.sh that skipped the package that
  requested unzip and instead used the origin template.
- Pass CFLAGS, CXXFLAGS and CPPFLAGS through the environment and unset
  them once the package has been installed.
- Do not show the dependencies required for a pkg more than once time.

--HG--
extra : convert_revision : 731135558d29787ab5178b80df3578420872709d

helper-templates/pkg-config-transform.sh

@@ -1,4 +1,5 @@
-# This script will transform the pkg-config files with correct
+#
+# This helper will transform the pkg-config files with correct
 # directories pointing at PKGFS_MASTERDIR specified in the config file.
 #
 pkgconfig_transform_file()