Modified IVirtualAnalogSensor interface to be more general

Changed setTorque method name to updateMeasure
Added also getChannel and getState methods
Thrift - fixed generation of the list of generated files
do not pick an IPv6 address for name server by default, not ready yet
add basic implementation of one-sided persistence
fix implicit cast that not all compilers support
add api for controlling persistence type
apply path fix for user plugin libraries from Juan G Victores, fixes #34
std::string -> ConstString until C++11
Fix License statement in README.md
[cartesian i/f]: added methods to deal with tip frame
adding the primarily support to Lua in yarp
fixing lua-binding linking problem on windows (missing linker libraries)
make ResourceFinder return absolute path to working directory
handle rpath correctly on OSX [thanks Konstantinos Theofilis]
Require CMake 2.8.7
Policy CMP0011 is no longer needed
Set version before other checks
Cleanup cmake files and fix use of FindPackageHandleStandardArgs
Fix yarpbuilder build with YARP_USE_GTK2
Find Atlas quietly