Added alignment support and addSpacer method
put a gil release in the python bindings for ScriptNode::deleteNodes in case it triggers a python evaluation
Stopped ScriptNode.deleteNodes reconnecting nodes outside the script

This is so the deletion process doesn't reconnect nodes to the viewer (for example), which is a waste of effort and can cause fiddly problems like python/gil lock issues
Added a channel mask feature to GafferImageUI::ImageView.
This commit allows the user to view different channels by pressing the coresponding key for R,G,B and A.
added option to screen grab app to take a cmdsfile

so rather than having to try to hack a load of commands in to one string, we can just pass a path to a file full of lots o' commands
Merge pull request #478 from bentoogood/screenGrabCmdsFile

added option to screen grab app to take a cmdsfile
put a GIL release in Gaffer.Plug.setInput python method
added test to make sure the script node doesn't reconnect nodes that aren't its descendants
Merge pull request #479 from davidsminor/graphpherShaderDeleteHangFix

Graphpher shader delete hang fix
Updated ViewportGadget for IECoreGL::Selector change.
Merge pull request #480 from johnhaddon/scopedSelector

Updated ViewportGadget for IECoreGL::Selector change.
Merge pull request #474 from goddardl/ImageViewerRGBASelection

Added a channel mask feature to GafferImageUI::ImageView.
Bumped version number and updated Changes file.
Added Application._executeStartupFiles() method.

This may be used to "borrow" the configuration files from another application. The screengrab app uses it to ensure that the screengrabs made are representative of the gui app.

Fixes #354.
Merge pull request #481 from johnhaddon/startupFiles

Added Application._executeStartupFiles() method.
Fixed a bug in the pixel value inspector.
Closes issue #401.
Added GafferImage::RemoveChannels.

* Added the GafferImage::RemoveChannels node to allow channels to be removed from the image stream by specifying a selection to keep or remove.
* Added test cases for the above.

Note: This pull request is dependant on the cortex pull request #59.
Added an Enum for the two RemoveChannels modes and updated the test cases for clarity.
Simplified the hashing of the channel names.
Removed unnecessary flags on the ChannelMask knob.
Moved the RemoveChannelsMode enum into the RemoveChannels scope.
Merge pull request #459 from goddardl/RemoveChannels

Added GafferImage::RemoveChannels.