Issue #83 Updated record_string to correctly escape quotes and backslashes 

...when turning the datashape into a string.

This fixes a problem in blaze where converting from one datatype to another would throw errors when transferring the datashape from one source of data to another.
Several tests have been added and all tests pass.
@cpcloud I don't think I understand what you are asking for with the first comment. (I like having individual tests for each case that I want to try instead of glomming them into one large test)
test_spaces_01 is simply the first test of dshapes with spaces in the fields.
Would you prefer the name "test_first_dshape_with_spaces_in_the_field"?