[APBeta] New annotation feature in 2.0b30

[Paul Rodman]

This release sees the beginnings of a new Annotation feature. This  
feature is similar to the old Catalogue Annotation feature, and  
replaces it. It's designed to allow you to "annotate" specific objects  
with notes. This feature is not in the list of new features for this  
version.

This can now be done from various places (the Objects tab, the  
Observations tab, the Catalogue display window, and others to come.).  
Annotations are cross-referenced by ID, so that an annotation for M31  
would also appear for NGC224, etc. You can have multiple annotations  
per object, and so on. Annotations for solar system objects are also  
now allowed.

If you have existing Catalogue Annotations, they will be imported into  
the new database via a background thread when you startup this version  
for the first time. This will be indicated by a green pulsing "Anno"  
icon near the top right of the plan window. Since this import process  
has to build cross-references it might take some time, and during that  
period the Annotation features will be disabled. PLEASE DO NOT QUIT  
FROM THE APPLICATION UNTIL THIS PROCESS IS FINISHED. i.e. the green  
icon thingy goes away.

This feature is a work in progress. Other items still to be addressed  
include:
- Allowing display and editing of ALL annotations at once.
- Import and export of annotations
- Script access to the annotations
- Printing of annotations and including them in printed reports, etc.
- Catalogue search by annotation

Please be patient.

Paul R.