shorter names on subterm uris. new sub zone ui padding.

Ignore-this: 98adeed8f38d043a61bc48245cf63e2a

darcs-hash:20130609094158-836b1-fe2c44369b89dc7c6dbb1eb77da51a4c47a15e63
guard against an abspath getting into a uri

Ignore-this: 95801647474b0a52e9ed429aaad2fbe0

darcs-hash:20130609094322-836b1-180aacc78847efc200a161e59d6f29e067e6788d
error if we have multiple expressions on one subterm

Ignore-this: f2f7f687ce0cf1f01df300a523f78243

darcs-hash:20130609094335-836b1-e4e350e11c1f615c6abd077945575384d3959f12