try to fix some obvious bugs about groups

[braindevices]

Hi All,
I just upgraded to 2.10 and I found some bugs immediately.

1. in the right-click-menu there is no move-to-group but 2 remove from group instead.
2. I like the new add/remove/move panel, but the scrolling is not
   working, which is a big problem. Because I have lots of groups which
   cannot even fit into the full screen height after expansion.
3. no way to expand or collapse all nodes

I tried the dev version, all problems still exist. Here is my fixation.

Cheers,

W.L.

[braindevices]

After 2.10 the BibtexEntryType.java is changed a lot. The optional fields and required fields are very different. If one need the field order is exactly the same as the 2.9.2, one should manually define the order. 2.10 also fixes some bugs in entry sorting. Some entries will be always different from 2.9.2. So I think backward-compatibility does not make sense any more. If one really want the bib file arranged in the same way as 2.9.2, he should just use 2.9.2. Upgrade all client to 2.10 makes more sense here.