docs(guide/expression): remove reference to `NullPointerException`
chore(doc_gen): add task to run doc-gen specs
fix(doc-gen): correctly transform index files

Closes #3021
docs(guide/controller): fix an error in the scope inheritance example

The chained scope creation example at the bottom of this document was using the childCtrl to create the babyScope, instead of the childScope.
docs(tutorial): add experiment showing reverse sort
docs(ngMock/$httpBackend): fix testing example

Closes #3075
docs(guide/e2e-testing): clarify description of input(name) selector

The description of the input selector made it seem that you were selecting
an input element based upon it's name attribute. In reality, you are
selecting an element by the string in the ng-model attribute.
docs(ngPluralize): improve wording
docs(ngBind): clarify some of the writing
chore(build): temporarily add more logging to debug flakiness on CI
fix(compiler): corrects component transclusion on compilation root.

Closes# 2155
style(ngRepeatSpec): fix up colons and iit
chore(build): change logging level for e2e tests to info
docs(misc/faq): remove obsolte t-shirt instructions
chore: remove jstd leftovers
chore: update karma to 0.9.4

And also add shared config to make karma configs a bit simpler.
chore: clean up angularFiles.js
chore: set up Sauce Labs with Travis

This should not affect the Jenkins build at all.

Now, the Travis build uses Chrome on Sauce Labs, which in theory gives us opportunity to use any
browser/platform that Sauce Labs offers.
test(docs): fix invalid paths
chore(gitignore): add .agignore

I use a .agignore file to skip the build directory and some other files
while searching using Ag (see
https://github.com/ggreer/the_silver_searcher).