TODO
-----

(-) Add filter_flags, disable_as_needed, disable_no_undefined functions
(-) pisitools.dobin() needs a destinationFile parameter to rename the binary
(-) pisitools.dodoc() may need an optional mode parameter for chmodding installed
    documents
(-) pisitools.dodoc() does not allow passing a directory as source
(-) pisitools.dobin() is already doing what pisitools.doexe() is doing
(-) pisitools.dolib() and pisitools.dolib_so() are carbon copies!
(-) Unify all dolib* stuff into one function
(-) rename() could be dropped in favor of move()
(-) pisitools.dosed() does not provide all sed functionality. It only supports
    substitution. Rename the function or add support for other sed commands.
(-) It is not clear which function takes source file paths relative to workDir or
    relative to installDir (dosed, insinto -> workDir, rename -> installDir).
    We may consider using different module names to distinguish these like
    sourceutils, installutils, etc.
