Refactoring of container loader.

- Overall simplification
- Define the Loader API
- Adds a lot of tests
Adds webapp2 as a requirement, to fix test suite.
Internalize cached_property decorator and removes webapp2 dep.
Simpler factory getter, no need to reimplement cache on top of cached_property
Fix builtins implementation problem, now uses __builtin__ instead of __builtins__ (cf https://docs.python.org/2/library/__builtin__.html and http://stackoverflow.com/questions/1184016/why-builtins-is-both-module-and-dict)
Test coverage enhancement and reference implementation for xml loader.

- Exceptions for basic types are now closer to bare python type cast errors (ValueError instead of TypeError).
- <reference> tag now works again as expected (may still need advanced testing).
- Adds tests and pragma no cover annotations.
- Adds a base TestCase class which logs to DEBUG level the test methods called.
- Removes unused test.
Adds test for container parameter setters/getters. Fix float test in simple tests which may fail on python 2.7 at least, according to travis builds.
Looks like the container api for multi get/set is not yet very polished, this commit gets something up and running but multiget/set should get a further/deeper look/think.
[Tests] add simple service definition test using builtin module (os.path)
[Doc] bootstrap sphinx dir structure
Add flags to configuration so we can indicate that a collection should be lazy loaded or not. The set_parameter vs define logic should be grouped to simplify this.
[Tests] Fix output format so we retrieve the flags in tests. This API should not be considered stable yet.
dic: shorter representation of references
Merge remote-tracking branch 'remotes/origin/dev-refactoring-loader'

Conflicts:
	rdc/dic/definition.py
log: remove default debug level in logger so were not spammed
repr: adds tests for new representation of Definitions, and fix a few bugs that tests unburried.
dic: proof of concept of injection decorator on container instance.
huge bug in scopes, miscreating instances even in CachedScope, fixed, and tested.
adds experimental support for thread local scope, giving each thread a different service instance.