Summer commit.

- We now use the `*.hpp` extension for all C++ headers.

- Removed redundant `awe` prefix on source code file names.

- Moved all sound source objects to the `Source` namespace
  and dropped the `A` prefix on sub-namespace classes.

- Beginning switch to use shared pointers for objects.

- Made `Aloop` into a class template to support different
  data types.

- Made `Afilter` into a class template with a channel count
  template parameter. This is done to allow support for
  filter specializations based on the channel count.

- Moved `Aframe` template to its own file and added missing
  operator overloads to it.

- Refactored the IIR filter interface.

- Separated the sample class into two: a `Asample` object
  that holds the sound data and a `Sampler` object that
  renders an `Asample` into an audio track.

- Added SoX Resampler library for proper audio resampling.

- Added experimental audio Maximizer and Monitoring filters.

- Added `.vimsettings` file to standardize code formatting.

- New Makefile (based on mbcrawfo/GenericMakefile).

- Some undocumented bug fixes.