[PATCH] Database shapes and start arrow

[Jim Ursetto <jim 3e8 org>]

Hi,
I noticed the database shapes set can change the end arrow type on references but
not the start arrow.  I was just curious if this was omitted for a reason.

I thought it might be useful, so I implemented start arrows at:

https://raw.github.com/gist/2468876/5046e5d3ef4174379eab24e836749504ccdef294/dia-0.97.2-dbarrow.patch

It is against HEAD but applies fine to 0.97.2.

There seems to be no downside except old files will print some warnings until you re-save: 

1) loading old file into new dia: will warn to stderr that start_arrow is
    missing for all references, and default correctly to no start arrow
2) loading new file into old dia: will ignore the start arrows

Jim