InStr Comparison between two values on the same row in the same DataFrame
Enhancement Request:  
- InStr Comparison between two values on the same row in the same DataFrame

Would be great if pandas would enable some 'instr' functionality between two columns.

For instance, being able to tell when the contents of one value exist in another:
- Excel does this in the following manner:
  `=instr(0, a1&"."&b1, c1, vbTextCompare)`
- In Teradata SQL (not ansi compliant):
  `select databsename, tablename, requeststring,`
  `index(createstring, databasename||'.'||tablename)`
  `from dbc.tables;`
