separate compiler and linker flags

fixes #336
npwrapper: add missing dependencies, also reorder a bit
cmake: remove -lpthread from linker_flags

also link against CMAKE_THREAD_LIBS_INIT where missing

cmake: link crashuploader against thread libs

cmake: add some more linker libs

cmake: link webcore against thread lib

Conflicts:
	cmake/platform/unix/compiler/GNU.cmake
	src/shared/mcfcore/CMakeLists.txt
cmake: OpenSSL is only required if we build curl

Conflicts:
	CMakeLists.txt
	src/tools/mcf_upload_cli/CMakeLists.txt
npwrapper: add --no-as-needed and link against GTK