Remove toolbar zoom buttons in OPIView.
OPIView: reinstate two zoom buttons on toolbar.
EDM mode: first pass at OPIShell implementation.
Enable closing OPI shell as well as editors and views.
EDM mode: allow EDM mode as an option when creating OPIs.
Middle click puts PV on clipboard
EDM Mode: use selection clipboard for PV on middle click
OpiShell calculates window borders after opening.

This allows the window size to take into account window borders
with differing dimensions.
Added path to DisplayModel, which prevented some windows from opening.
Added support for macros to OPIShell
Initial commit of EDM Style symbol widget
If macro opi.dir is specified, use it as working directory.
EDM Mode: handle null values passed to clipboard...

... on middle click.
EDM Mode: remove spurious print statement
EDM Mode: add symbol number as property of symbol widget

This allows dynamic selection using rules.
Converter: make EDM OPIs the default for related displays
Converter: use new symbol widget for EDM symbols

I've hard-coded widget sizes, because it's not easy to find
them from the OPI file.
Converter: handle symbol width in filename.
Rename EDMSymbolWidget plugin as widget.edm
Added tycho build files for Edm Widgets