pkg-config: fix cflags/ldflags on linux

* call configure from the internal-glib dir, specify libiconv=gnu
* enable libiconv dependency on non-freebsd platforms
Update deprecations for using OHAI (Ohai)
add comment that this software defn is deprecated

i'll add a bit more background in this commit message, with the stated
qualifier for anyone in the public (non-Chef Software, Inc. employees)
stumbling upon this that THIS IS NOT LEGAL ADVICE, IANAL, etc.

discussed with Adam J about dynamically linking vs statically linking
this due to LGPL concerns and we believe that there's no concerns over
statically linking libgcc, and that we've been cargo culting this
particular solution for a few years for no reason.
Merge pull request #203 from fujin/202-patch-pkg-config-cflags-ldflags

pkg-config: modify linux environment variables
Merge pull request #204 from opscode/sethvargo/deprecations

Update deprecations for using OHAI (Ohai)
Merge pull request #205 from opscode/lcg/deprecate-libgcc-defn

add comment that this software defn is deprecated
Bump the default version for libxml2 to a secure version.
Remove the deprecated version calls from bundler and preparation.
Update nokogiri to 1.6.2.1 and add the required Mac depedency.
Fix the healthcheck issues on Solaris for gdbm.
Make sure same env is used across configure and build for liblzma.
Upgrading rebar to make sure the TEST macro is indeed defined when compiling for tests
Merge pull request #208 from opscode/jr/upgrade_rebar

Upgrading rebar
Merge pull request #206 from opscode/sersut/omnibus-310

Chef Client CI Issues
Revert 2a89c31

The change to the jre config broke builds and upon further review, the
way in which jre versions are hard-coded will prevent projects wishing
to override the default_version provided here (which doesn't align with
the hard-coded version causing some of the breakage issues).

So for now, we're reverting this to get back to a working state.
Add libffi dependency for Debian to ChefDK
Link to omnibus-ruby from README [trivial patch]
Test for RHEL 5 gcc when building dep-selector-libgecode
make 1.1.28 the default version of libxslt
Merge pull request #215 from opscode/nls/bump-libxslt-default-version

make 1.1.28 the default version of libxslt