RF: microphone improvement: chnls as argument to record

- main motivation is to expose the chnls parameter, if needed.
  default remains 2 chnls (stereo), but might want 1 channel for
  smaller file sizes, or when down-sampling from 48000 to 16000 to use
  google-speech. pyo had a bug that messed with downsampling 2-channel
  data (fixed in pyo rev 1115).
Merge pull request #325 from jeremygray/master

RF: tweak to audio recording (enable mono recording as a possibility)
ENH: remove .bak files

Came from

$> git log **/*.bak
commit 310d6daba8e6dcc448271eb1b2b35a0876cfa934
Author: Sol Simpson <sds-git@isolver-software.com>
Date:   Tue May 7 06:24:52 2013 -0400

    ENH: updated comments, default yamls, code
Merge pull request #326 from neurodebian/master

sloppy removal of  .bak files
BF: Replaced iohub eye_tracker demo update

- images are all now ones taken by Sol Simpson; free to use in any way
by anyone, license.
- all images are now jpg, none larger than 460 K.
Merge branch 'master' of git://github.com/psychopy/psychopy
updated .gitignore to skip .bak files
Merge pull request #327 from isolver/master

BF: Replaced iohub eye_tracker demo update
BF: LC Technologies eye tracker interface

Fixed an outstanding issue related to calculation of the eye tracker
sample delay to the iohub server; sample delays and psychopy / iohub
sample times are now correct. Thanks to LC Tech. for providing the
necessary info to fix the problem.

EN: Added the Tobii 3D gaze relative data type to iohub EyeTracker
samples; this will allow feedback to be provided regarding the head
position within the 3D head tracking space the system can support. Use
of this data TBC.
Merge branch 'master' of git://github.com/psychopy/psychopy
Merge pull request #328 from isolver/master

BF: LC Technologies eye tracker interface; ENH: Tobii sample data
ENH: applying a Hamming window to generated tones

- reduces clicking at tone offset
- can override using hamming=False if desired
Merge pull request #329 from jeremygray/master

Hamming window for sound-from-freq
ENH: microphone recording: enable selection of stereo or mono
Fixed always-empty recent files list
Merge pull request #330 from piwaniuk/recent-files

Fixed always-empty recent files list
ENH: microphone.getRMS() returns "loudness" of audio

- from .wav file or from array (1D, 2D)
- use to give subjects feedback about whether they are talking loud enough
RF: minor clean-up in microphone and sound.py
RF: BufferImageStim accepts mask and pos params

This allows dynamic grab of a small screen area w/ mask, e.g., for
gaze-contingent displays.
Merge pull request #331 from jeremygray/master

ENH minor enhancements, RF's