[schema view] only catch key errors

[schema view] improve it slightly by attributing the same color to rdef of the same relation type

[rset] Add a line break the first result in repr of multiple rows rset Improve readability of rset while debugging by aligning the first value with the others if the rset have multiple row. This first line was usually not read as it' was on the same line that the first part of the repr ("<rset <RQL>, (%i rows) ...")