added centerX and centerY options
now using text column for generating labels
added gui editor for label plotter text column
added "Edit session state" menu item
Added fill color as a selectable attribute
Added caching to DynamicColumn and AlwaysDefinedColumn
keyType now derived from first variable if not given in metadata session
state.
performance improvements

Change-Id: Ieb35a9206dc1c1a41b76c37976fda0af9089e104
fixed bug where flattening a function lost the bindThis value.

Change-Id: Idf652591f62b9b8b93e6a27952bf0bafeeba5c18
Functions can now be compiled and returned from evaluateExpression().

Change-Id: Id1e96dd33dd75a42ee12bd48e5a007e4ec96b598
fixed bug where loadFile() wasn't calling callback
Merge branch 'master' of https://github.com/IVPR/Weave into aws-release