do not explode if config[:addons] is an array
Inject /etc/hhvm/php.ini in PHP's configure for HHVM

We need to run this before paranoid_mode disables sudo

This fixes https://github.com/travis-ci/travis-ci/issues/2863 and
https://github.com/travis-ci/travis-ci/issues/2523.
Pleasing @meatballhat
Merge pull request #322 from travis-ci/ha-bug-hhvm-ini-fixes

Inject /etc/hhvm/php.ini in PHP's configure for HHVM
Merge branch 'master' of github.com:travis-ci/travis-build
make sure Data::Var#secure? returns true/false
Disable spec failing because of case insensitivity on Mac OSX

I am not sure how this spec ever passed.

Apparently `[ -f Requirements.txt]` always matches on Mac OSX (case
insensitive file system), even if only `requirements.txt` is present.
Therefor this spec will always fail because the bash script runs the
first branch of the `if` statement, not the second one.
Refactor towards sexp changes

Some refactorings and cleanup in order to work towards re-applying
the sexp changes.

This mostly makes all `Build::Script` implementations use
`sh.[dsl_method]` and stops including `Dsl` to `Build::Script`. Instead
`sh` will always be the current `Shell::Node`.
move secure var obfuscation to the dsl
coverity_scan addon (does not have any tests)
firefox addon
sauce_connect addon
android script
C script
clojure script
cpp script
erlang script
go script
haskell script
node_js script