Updated parse_struct_item to be able to handle struct field names that are quoted.
Quoted names are required when there are special characters in field names like spaces, commas, etc. (basically anything except [:alphanum:] and "_".
Added tests to the DataShapeParser test suite to try to test as many strange field names as possible.
Merge remote branch 'origin/master'
Added test to check if integer-only field names are accepted by the quoted_name parser. The test passes.
Merge pull request #110 from nevermindewe/master

#107 Datashape parser should allow quoted field names