Fix RDS ModifyDBInstance (issue 104)
Fix terminate for autoscaling instances
Assortment of small text fixes
Widespread delint
Fix S3 download filenames
Security groups should not support tagging
Need to refresh view after adding security group
Ensure that status bar is always visible
Fix issue with ElasticWolf opening on Firefox start-up.

 * Add Makefile rule for installing into Firefox

 * Use build directory in Makefile

 * Add build directory to .gitignore

 * Stop 'make clean' deleting all XPI files from project parent directory

 * Remove unnecessary files from XPI file

 * Add Firefox-specific preferences file which omits defaultChromeURI

 * Add Firefox installation instructions to README.md