Synchronize
Correct the exception catching.

The exception thrown did not have the good type.
As a result, printing for example
robot.featureComDes
would crash.
Fixes issue #19 : Remove wrong commands of python metatask FeaturePosition.
Remove useless header.

The right one is feature-posture.hh
Added type and dimension case for reference vector
Added possible posture ranges
Merge pull request #20 from francesco-morsillo/master

Smooth changings for sot-core
Correct documentation generation by adding sphinx.
Correct LD_LIBRARY_PATH for test and remove hard-coded 'plugin'