empty root for input-devices code rebase-and-merge tree
input: Added axis-only controller impl. using Linux `evdev`

  * TODO: add button support, and separate the platform-specific
    driver code into a subclass of `Controller`.

Note that the controller code is currently untested (though it
compiles and is based on code that was working last year...)
Reorganized controller code for cross-platform support

  * Moved platform-specific functionality into EvDevController

  * Made Controller a virtual base class.
util/ArrayAccessor: added some missing #includes
Axis: decl an ext.-template instantiation for assoc. MappedEventSource type
input/Axis.hh: corrected doc-comment on move constructor
Placed all declarations/namespaces inside namespace "crisp"
Removed CMakeLists.txt in preparation for merge into master
Merge branch 'input'
Added 'crisp-input' library target.