Merge branch 'release/0.2.2' into develop
setup: next version is 0.2.3
reduce: fixed typo in docs (Sphinx does not like "``s" sequence)
setup, MANIFEST: added two forgotten files to the distribution
TODO: moved a task
cluda: moved api discovery objects to a separate module

And transformed constants to functions in order to work around autodoc limitations.
doc/history: added a change
cluda: added documentation for Module and moved it to the submodule level
cluda: documented OutOfResourcesError exception
doc/cluda: fixed label position
cluda/functions: fixed references to Module
TODO: finished task
cluda: renamed (source) Module to Program to avoid confusion with CLUDA modules
test/cluda/cluda_basics: removed tests which relied on hidden attributes
test/test_cluda: renamed modules to programs (since the class is Program now)
cluda/api_discovery: renamed api() to get_api() to avoid ambiguity
cluda: extracted common functionality of cuda and ocl to cluda.api
cluda/api: fixed Context constructor signature
cluda/api: fixed rST directive
cluda/api: hid Kernel, Program and StaticKernel signatures from docs