relocate ROS packages to /opt/ros/${ROSDISTRO} (resolves #214)

This version fixes build problems with a ${prefix} other than /usr.

Update the setup instructions to reflect the use of ${ros_prefix}.

Following standard convention, place ROS/Catkin packages under the
prefix /opt/ros/${ROSDISTRO} (exported as ${ros_prefix}) rather than in
the usual ${prefix}.

updates and minor tuning at the end of July 2014

Executing 'bitbake packagegroup-ros-world' shows the warning:
WARNING: QA Issue: collada-dom rdepends on libpcrecpp but its not a build dependency? [build-deps]

On a clean build, 'bitbake collada-dom' fails with:
| Linking CXX shared library libcollada-dom2.4-dp.so
...
| .../build/tmp-eglibc/sysroots/x86_64-linux/usr/libexec/x86_64-oe-linux/gcc/x86_64-oe-linux/4.9.1/ld: external-libs/pcre-8.02/libpcre_local.a(pcre_compile.c.o): relocation R_X86_64_32S against `.rodata' can not be used when making a shared object; recompile with -fPIC
| external-libs/pcre-8.02/libpcre_local.a: error adding symbols: Bad value
| collect2: error: ld returned 1 exit status
| make[2]: *** [dom/libcollada-dom2.4-dp.so.2.4.0] Error 1

This commits adds libpcre as dependency, and resolves the issue.

This commit updates to version 1.5.3 and removes the local patch
that has been merged in version 1.5.3.

Executing 'bitbake packagegroup-ros-world' showed the warning:
WARNING: QA Issue: image-rotate rdepends on nodelet but its not a build dependency? [build-deps]

On a clean build, 'bitbake image-rotate' failed with:
|   Could not find a package configuration file provided by "nodelet" with any
|   of the following names:
|
|     nodeletConfig.cmake
|     nodelet-config.cmake
|

Hence, this commit adds the missing dependency on nodelet.

Define a ROSDISTRO variable to record the current ROS distribution
code name for use within ROS-related recipes.

It seems as if the archive was updated at some point in time
without spending a new version number. This commit was needed
after I cleaned all downloads from the meta-ros layer.

Add eigen-conversions as a dependency to image-rotations

Some version updates and minor tuning

some improvements to the speech-tools recipe

Updates till late June 2014

libpoco: use system libraries instead of bundled versions

Poco comes with bundled versions of SQLite3, zlib, expat, etc.
Adding the ``-DPOCO_UNBUNDLED=On`` option to CMake makes it use the ones provided by OE.

The patch provided upstream is part of 1.0.7 and hence is removed.