silenced new gcc warnings

cmake: MSVC compatibility fix for packaging

cmake: added target PACKAGE_SRC_TAR

fixed the previous jpeg change

added chanelog for version 1.7.1

vigranumpy: improved documentation (using new boost_python configurat…

…ion options)

added link to binray distribution

simplified randomInt()

move by at most 1.5 in cannyFindEdgels3x3()

changed border treatment to reflect in Kernel1D default constructor

changed documentation to conform to the new default border treatment