Check C source dependencies in needs_compile
Add test for C dependencies
Manually clean up paths

Using code:set_path/1 with very large paths is very slow on larger
projects.  On my mid-sized project, it seems to take around .4s per
call.  Emulating the call with direct path removal (using
code:del_path/1) seems to be quite a lot faster.
Merge pull request #344 from evanmcc/pevm/set-path-speedup

Manually clean up paths.
fish shell completions for rebar
added fish support for './rebar'
Add typer target

This patch adds a typer target to the Makefile. It makes it
easier for developers to start adding specs to the codebase. It
also as a build_plt target with the built-in applications typer
needs to analyze rebar.

This also includes the Erlang version in the generated PLT file.
typer and dialyzer targets use this file. Finally, the distclean
target removed the versioned PLT file.
Merge pull request #352 from tuncer/rebased-309

Add typer target (rebase of #309)
Merge pull request #351 from joedevivo/master

fish shell completions for rebar
Normalize whitespace
Merge pull request #293 from liskin/port-deps

Check C source dependencies in needs_compile