Use objDir (renamed to workDir) for more than just object files.

Rationale: Previous plastering of hash calls and other "unique path"
building all over the code was a manifestation of inconsistency and
code duplication. Now, the hash of the relevant parameters is only
calculated once, and all compile-specific files are stored in that
subdirectory.

Actual object files are now stored in a subdirectory of workDir. The
.rsp file is thus now preserved, because 1) it takes up insignificant
space 2) it's referenced in --chatty output.

This commit also changes the executable file name for generated
executables to no longer include the hash. As a result, users no longer
see the hash as part of the process name in process lists and
pkill/killall tab completion.

This commit also moves the .deps file into the aforementioned work
directory, a suggestion that was raised before.
rdmd: Don't attempt to delete inexisting objDir
rdmd: Ignore existing .deps file with --force
Merge branch 'master' into rdmd-fixes-20120224

Conflicts:
	rdmd.d
rdmd: --build-only should default to main file dir, not current dir
rdmd: Absent files should indicate a dirty .deps
Merge pull request #27 from dawgfoto/master

rel2abs was deprecated
dget script

- use github API to resolve repositories
- either unpack master zipball or clone
Merge pull request #28 from dawgfoto/dget

dget script
Merge branch 'master' into rdmd-fixes-20120224

Conflicts:
	rdmd.d
rdmd: Update comment regarding --build-only
rdmd: Minor --force optimization
Merge pull request #19 from CyberShadow/rdmd-fixes-20120224

Use objDir (renamed to workDir) for more than just object files.
fix build break
Support other compilers in rdmd.
Use defaultCompiler in rdmd's help message.
Merge pull request #29 from alexrp/master

Support other compilers in rdmd.
An improved version of ddemangle.

This one uses std.regex to replace all occurrences of mangled symbols
per line. Sometimes this is needed when the line just happens to contain
the wrong character sequences (_D...), which cause a real symbol later
on in the line not to be demangled, if only the first match is
attempted.

It also uses std.getopt for future extensions (ala c++filt, if we ever
decide to do that).
Remove debugging code.
Merge pull request #32 from quickfur/new_ddemangle

Improved version of ddemangle