Solve issue #103: Does not build on Linux <2.6.17, issue #108: unused_result warning on g++-4.8.1
Merge pull request #109 from adamcavendish/master

Solve issue #103: Does not build on Linux <2.6.17, issue #108: unused_result warning on g++-4.8.1
fixed selection of poll/epoll impl, closes #110

this patch also gets rid of an unused-private-field-warning
when compiling w/o context switching
Make maximum message size configurable.
Merge pull request #112 from mavam/topic/variable-msg-size

Make the maximum message size configurable.
Fix building libcppa as a submodule
Merge pull request #113 from w0land/fix_cmake

Fix building libcppa as a submodule
Merge branch 'master' into unstable