ghc: remove 10.8 bottle

See #22847 - the bottle is broken on Xcode 5.
pianobar 2013.09.15

Closes #22868.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
Rust 0.8

Closes #22867.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
nexus 2.6.3-01

Closes #22864.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
tup 0.7

Closes #22858.

Signed-off-by: Adam Vandenberg <flangy@gmail.com>
SoftwareSpec: remove dead code
Infer dependencies from download strategies and URLs