resolve_tilde_path was unnecessary as File.expand_path provides this behaviour
start working on change log for v2.1
specify a slightly larger server block size on RP for improved performance
preliminary autocompletion support: samples, fx, synths, lang
better autocompletion context, chord, scale, and FX args
don't flash autocompletion box with no matches
only redirect stdout to logfile on Windows
Added QtConcurrent for QtConcurrentRun

This fixes compilation errors on Ubuntu 14.04.1 (required by mainwindow.cpp)
Added instruction for running under generic linux

JACK doesn't start automatically when running the script. Added instructions for starting it manually. 

Configuring JACK for low-latency performance is not difficult, and there are several guides for how to do this online, but I didn't know a good up to date walk-through to point to. The jackaudio [wiki](https://github.com/jackaudio/jackaudio.github.com/wiki) might be a good choice?
Fix location of samples directory within Mac app bundle:

* samples are now correctly autocompleted on the Mac
pull in QHash header
Make default build target sonic-pi except for Macs where it’s Sonic Pi
update twitter handle to a full link
Toggle preference pane with cmd-p
binary is now sonic-pi on non-Mac platforms
auto log all system calls when booting external processes
move pref widgets around for better layout (and to avoid clashes)

Fixed #158
use a smaller number of audio busses on Raspberry Pi - 64
turn debug mode on and output to boot.log
ignore sonic-pi binary not Sonic-Pi