Adds some filepath utility functions to the Processor
base class.

Signed-off-by: Jim Teeuwen <jimteeuwen@gmail.com>
Removes individual toggle buttons for source processors.
Replaces them with a single button which opens the plugin
configuration dialog. This will be presenting all configuration
settings for each individual component of the Go tools plugin,
as well as the option to enable/disable specific ones.

Signed-off-by: Jim Teeuwen <jimteeuwen@gmail.com>