docs(config): Document `client.args` config
fix(config): allow CoffeeScript 1.7 to be used

CoffeeScript 1.7 requires a register call to be made. This change is still backwards compatible with older versions of CS because the needed part, the require, is still done. The register function fails but it is wrapped in a try catch block so it fails silently.
test: show proper stack traces for coffee script files
feat(reporter): use spaces rather than tabs when formatting errors
feat(preprocessor): allow preprocessor to cancel test run

Now a preprocessor can return an error, which
  - stops preprocessing (does not trigger other preprocessors),
  - cancels the test run.

This changes the preprocessor API - preprocessor's `done` function accepts two arguments:
  - an error (`null` if no error),
  - content.

The change is done in a backwards compatible way - if a preprocessor calls `done` with a single
string argument, it is treated as no error.

Closes #550
chore: update contributors
chore: release v0.11.14
Merge pull request #845 from gfxmonk/document-client-args

docs(config): Document `client.args` config
Merge pull request #903 from eddiemonge/patch-1

fix(config): allow CoffeeScript 1.7 to be used
docs(readme): add more info about the basic concepts
chore: update copyright year range
feat: remove dependency on coffee-script

Karma never used coffee-script directly, it's just so that people can write config file in CoffeeScript.

Now it's only required if available. That means, if the developer wants to use CoffeeScript syntax, he has to install coffee-script on his own (put it in package.json).
feat(config): better error when Coffee/Live Script not installed
fix: serving binary files

For binary files, we can't cache the content as a string (utf8), we need to use a binary buffer.

All the preprocessors are currently implemented to deal with strings, as that makes sense for text files. If we changed preprocessors to deal with buffers then each preprocessor would have to convert the buffer to a string, do the string manipulation and then convert it back to a buffer. I don't think that's worthy as there are no binary preprocessors.

This change disables preprocessing of binary files to avoid weird errors.
It shows warning. If there is a reasonable use case for preprocessing binary files we can figure out something.

Closes #864
Closes #885
chore(gitignore): ignore .DS_Store for osx users
chore: added mocha debug task
Merge pull request #914 from gdi2290/patch-1

chore(gitignore): ignore .DS_Store for osx users
Merge pull request #917 from cironunes/mocha-debug

chore: added mocha debug task
style: fix typos
style: fix a typo