Fixed incorrect columns with multiple result sets

Changed to allow different columns in each result set by rebinding the
columns for every result set.
Added support for SQLProcedureColumns
Merge branch 'ctrychta-multiple-result-sets'
Merge branch 'procedure_columns' of github.com:ctrychta/nanodbc into ctrychta-procedure_columns
Merge branch 'ctrychta-procedure_columns'
Merge pull request #1 from lexicalunit/master

Update