Always use -DPIC/-fPIC when targetting x64

Fix link failure when making a shared object on Linux
cmake: MSVC does not understand -fPIC
review: improvement filterVertical_p_p and filterHorizontal_p_p
slicetype: Remove unnecessary initialization
slicetype: B-frames analysis integrated
slicetype: uncrustified
Set all I frames as keyframes, change nalunittype decision accordingly.
slicetype: Handle Bframes immediately preceding an IDR correctly.
x265: remove -w short option for disabled weightp command
x265: emit a warning message if a short option is invalid
x265: print unrecognized short options as char instead of hex
x265: nits