Added a new option --dep-target to the compiler. This option allows to set the

Added a new option --dep-target to the compiler. This option allows to set the
target in the generated dependency file. The cl65 utility will use this option
to override the depdendency target, if actual object files are to be generated
from C input. So the generated dependency will not have the intermediate .s
file as target, but the final .o file, which allows to use the dependency
files without further processing.

git-svn-id: svn://svn.cc65.org/cc65/trunk@4660 b7a2c559-68d2-44c3-8de9-860c34a00d81