build: changing behavior to merge develspace

This patch makes the following changes:
 - Makes the default build behavior merge all develspaces
 - Removes the --merge-devel argument
 - Creates a new argument: --isolate-devel = 'not --merge-devel'
Notify users beta status for installation
Merge pull request #54 from davetcoleman/patch-1

Notify users beta status for installation
0.1.0
build: changing behavior to merge develspace

This patch makes the following changes:
 - Makes the default build behavior merge all develspaces
 - Removes the --merge-devel argument
 - Creates a new argument: --isolate-devel = 'not --merge-devel'
 - Updates documentation for this new behavior
Merge pull request #46 from jbohren-forks/merge-devel-default

build: changing behavior to merge develspace
OS X Notifications: Add the missing application icon again.
Added note about interface not being stable.
doc: fixup
Merge branch 'NikolausDemmel-patch-1'
fixup for releasing
Merge pull request #43 from NikolausDemmel/master

OS X Notifications: Add the missing application icon again.
build: made the --start-with option more robust

fixes #60
Merge pull request #62 from catkin/issue_60

build: made the --start-with option more robust
Merge
Documented run_tests for catkin