Code-signing of generated executables is usually done with "signtool" on
Windows. When cross-compiling on Linux this tool is not avaiilable,
however, osslsigncode can be used as an replacement.
Move common files to common folder
Move patch files to patch folder
Fix clean rule in Makefile (Remove /Dockerfile in path, he is already there)
Signed-off-by: Bensuperpc <bensuperpc@gmail.com>