Always pass -linker and -ldflags to mklib for shared libraries
This just makes the use of mklib more consistent throughout Mesa where
we always want to pass the linker and LDFLAGS when we might be making a
shared library.
Consistently cleanup the depend.bak files created by makedepend. Also,
realclean has been changed to use a single find command, which speeds it
up considerably.
Improve the behaviour of the build system wrt depend files.
- Remove the -Y option for makedepend, so that the standard
directories are searched
- No longer pipe the multiple errors that the -Y option caused
into /dev/null -- we want to know about these failures.
- Fix up a few other misc makedepend failures.