Options to load and watch directories of tools, auto reload on update of any tool.
Allow tool panel to contain a <tool_dir dir="foo" /> element. Tools in such a directory will be loaded at startup time.

Additionally, if watch_tools is set to True in config/galaxy.ini and watchdog (http://pythonhosted.org/watchdog/) is available to Galaxy - all tools will be dynamically reloaded as they are modified and new tools that are added to the tool_dir directories will be dynamically populated (no need to restart Galaxy).
Merged in jmchilton/galaxy-central-fork-1 (pull request #509)

Options to load and watch directories of tools, auto reload on update of any tool.