wxwidgets: keeping in-source build (resolves #299)

This commit provides the autotools-brokensep class and uses it for
the wxwidgets recipe.
The autotools-brokensep indicates that this package currently cannot
handle out-of-source builds, and hence the in-source build must be
kept until this is resolved.
The autotools-brokensep class is a copy of the autotools-brokensep
class provided in the openembedded-core commit 006b8a78 [1].
To make this commit backwards compatible to even earlier versions
of openembedded-core, we provide this class in meta-ros ourselves.

[1] http://cgit.openembedded.org/openembedded-core/commit/?id=006b8a7808a58713af16c326dc37d07765334b12
libfreenect: backporting upstream patch to stop clobbering CFLAGS

Backporting following libfreenect patch:
https://github.com/OpenKinect/libfreenect/commit/
0cbb86ec982d3e79ad5efa9d1b2b16724ae89bc5

Without this patch, libfreenect would override all compiler flags,
including any machine specific compile flags
(e.g. -mfloat-abi=hard to compile with hard floating point).

We are backporting this patch rather than upgrading to v0.4.1
where this is fixed, as v0.4.0 introduced changes that break
compatibility with the current freenect version (0.3.2).
See https://github.com/OpenKinect/libfreenect/releases/tag/v0.4.0
for the breaking changes.
See https://github.com/ros-drivers/freenect_stack/issues/12
for additional discussion.
libfreenect: adding bash runtime dependency

Solves following warning:
QA Issue: libfreenect requires /bin/bash,
but no providers in its RDEPENDS [file-rdeps]
Merge pull request #301 from KristofRobot/libfreenect_clob

libfreenect improvements