More humanized error message

[eliangcs]

vcli prints whatever error message returned by the Vertica server, which is not very pretty:

localdev=> select title from movie order title;
Severity: ERROR, Message: Syntax error at or near "title", Sqlstate: 42601, Position: 31, Routine: base_yyerror, File: /scratch_a/release/30493/vbuild/vertica/Parser/scan.l, Line: 1014, SQL: u'select title from movie order title'

We should make it prettier at least like vsql (the official Vertica command line client):

localdev=> select title from movie order title;
ERROR 4856:  Syntax error at or near "title" at character 31
LINE 1: select title from movie order title;
                                      ^