Improve variable name 'filename' to be fifoFile.

'filename' is extremely generic.
The updated name 'fifoFile' communicates clearly that the file in
question is the the FIFO created to communicate with phantom.
Add a comment to clarify that file is run by Phantom

In particular, it's useful to note that it has it's own 'fs' module,
whose API differs from that of the core node.js module.
Document the internal API of using "!" to indicate a rendering failure.
Improve the name of the 'st' argument.

Before it wasn't clear what 'st' argument was for.

I updated it to be requestStatus, which makes it a little easier to
understand what the code is doing.
Tests should also use 'phantomjs' package for consistency.

The code has been updated to use the 'phantomjs' package to install and
locate the 'phantomjs' binary, but the tests has not.

If 'phantomjs' had install 'phantomjs' locally and 'phantomjs' was not
in $PATH, then the tests would fail, even though 'phantomjs' was
installed would be located by the code.

Now we test for phantomjs the same way the code would.
Merge pull request #26 from markstos/test-should-use-phantomjs-package

Tests should also use 'phantomjs' package for consistency.
Document many undocumented options.

The tabs here came out like a train-wreck. Likely will need some
whitespace reformatting.

I'll note that 80% of JavaScript projects on Github use spaces instead
of tabs, so they don't the tab-alignment is train-wreck problem:
http://sideeffect.kr/popularconvention#javascript
Merge pull request #27 from markstos/fifoDir-is-undocumented

Document many undocumented options.
fix whitespace for #27
Merge branch 'explain-the-bang' of https://github.com/markstos/phantom-render-stream into markstos-explain-the-bang

Conflicts:
	phantom-process.js
Merge branch 'markstos-explain-the-bang'
fix indentation
0.5.0
hacky windows support. fixes #10
added missing deps
Fix windows hack.
0.6.0
impl crop margin using the existing crop option for #32
0.7.0
rewrite render loop and fix various issues