qt: add proxy to options overridden if necessary.

If proxy is disabled in the gui but enabled via the command line, it needs to
be added to the override list.
travis: add non-default shell testing to travis.
Bugfix: Replace bashisms with standard sh to fix build on non-BASH systems
Bugfix: Replace bashisms with standard sh in gitian descriptors
Bugfix: Replace bashisms with standard sh in tests/tools
Disable App Nap on OSX 10.9+
minor txindex documentation improvement
Homebrew lang fix

Very small tweak to correct the language on Homebrew's sandboxing process.

Discussed in [this commit](https://github.com/bitcoin/bitcoin/commit/9fedafba4b903d7f3af044eb86dc313856e40b08).
Don't return an address for invalid pubkeys
Merge pull request #4954

9d7cd4c Don't return an address for invalid pubkeys (Andy Alness)
Merge pull request #5038

0b17964 Bugfix: Replace bashisms with standard sh in tests/tools (Luke Dashjr)
ab72068 Bugfix: Replace bashisms with standard sh in gitian descriptors (Luke Dashjr)
b77b4ed Bugfix: Replace bashisms with standard sh to fix build on non-BASH systems (Luke Dashjr)
d6b0539 travis: add non-default shell testing to travis. (Cory Fields)
Merge pull request #5053

27368e7 Homebrew lang fix (Dominyk Tiller)
contrib: revert changes to github-merge.sh in #5038
Merge pull request #5047

3e61eb9 minor txindex documentation improvement (Cozz Lovan)
Merge pull request #5041

1f9be98 Disable App Nap on OSX 10.9+ (Michael Ford)
Merge pull request #4976

27c3e91 qt: add proxy to options overridden if necessary. (Cory Fields)
Replace SignatureHash() with class TxSignatureHasher
Change SignatureChecker constructor and make its TxSignatureHasher a reference