Split pool code into dieter.pools
Add v8 dependencies
Move .gitignore to subdirectories
add :engine as option, defaulting to :rhino, prepare files for js engine abstraction
Basic JS engine separation for CoffeeScript.

Implemented jsengine.clj as a layer separating things that need to
execute JS from the actual engine implementation. Created stub code for
the V8 that mimics Rhino by signature, but is a no-op for now. Rewritten
cofeescript.clj asset compiler in terms of the new jsengine.clj instead
of binding directly to Rhino.
reorganize core project descriptor so that v8 actually works
on the v8 branch, the v8 engine is the default, right?
actual implementation of the v8 with-scope and call, still missing pooling
apply v8/call instead of plain calling it to splice the argument list
hamlcoffee asset compiler switched to flexible jsengine and tested with v8
Sets cache header to "forever" for production mode files, closes issue #10
bump clj-v8 dep version
expiration headers done right
Merge branch 'v8' of ../circleci-dieter into v8, other changes

Conflicts:
	dieter-core/src/dieter/asset/coffeescript.clj
	dieter-core/src/dieter/asset/hamlcoffee.clj
	dieter-core/src/dieter/core.clj

Also comitting changes that relate to extraction of the JS engine
selection logic into a separate namespace, implementation of the
JS engine based on the V8 JS engine, rewriting asset compilers
in terms of the new JS selection logic, adding an Expires middleware
that sets expires headers on cached dieter files (issue #10)
Merge pull request #26 from ivanstojic/v8

V8
test project for the issue #10 - adding expire headers
added extra comments to the code
add jna.library.path and lein-dieter-precompile to the project.clj
fix v8 asset loading when running from a jar, return hamlcoffee back to rhino temporarily
Merge pull request #27 from ivanstojic/v8

Bugfixes from our conversations and testing...