Merge 'and_or' into 'trunk'

r5977@Thesaurus (orig r5976):  arcanez | 2009-04-24 10:03:45 +0200
fix for x => { '!=' => [ -and => (1 .. 3) ] }
added parens for test

r5981@Thesaurus (orig r5980):  arcanez | 2009-04-24 18:52:50 +0200
remove parens from test, they do not matter
r6004@Thesaurus (orig r6003):  ribasushi | 2009-04-28 23:01:46 +0200
Revert r5976, trying something better
r6008@Thesaurus (orig r6007):  ribasushi | 2009-04-28 23:57:54 +0200
A much better fix for the x => [ -and, ... ] corner case