win-capture: Separate window finding source code

Because other capture methods may end up needing to share this code,
separate the window finding source code to window-helpers.c and
window-helpers.h.

This include a function to fill out a property list with windows, a
function to find a window based upon priority/title/class/exe, and a
function to decode the window title/class/exe strings from a window
setting string.
Update to version 0.6.2
linux-pulseaudio: Fix the default req. buffer len

This changes the the requested buffer length to 25ms.
linux-pulseaudio: Use defaults for pa_buffer_attr

Although these values aren't used in capture mode, set these to the
default values just to be safe.
linux-pulseaudio: Force stereo if unknown layout

This adds a check to change the capture settings to use 2 channels when
a channel number is encountered that would otherwise be interpreted as
SPEAKERS_UNKNOWN.
Update Ubuntu PPA install instructions
Merge pull request #286 from dodgepong/master

Update Ubuntu PPA install instructions
Fix sources context menu "Remove" shortcut for OSX
Add "Remove" shortcut to scenes context menu
Fix "Remove" shortcut (Del) to work for both scenes and sources
Add "Rename" entry to scenes context menu
Disable double click renaming for both scenes and sources
Open source properties on double click
Sparkle-Updater: Select delta update if available