Revision 665350

[thrift] gut Erlang exception handling

Summary: * move type field to tException from subclasses
          * add backtrace to tException
          * add oop:is_a
          * on exit, wrap exceptions in {thrift_exception, E} ... otherwise can't distinguish e.g. exit:{{tBinProtException, {tException, ...}}, Stack} vs. exit:{tBinProtException, {tException, ...} -- I hate erlang
          * all throws/exits to tException:throw which does the wrapping described above

Reviewed By: eletuchy

Test Plan: been using this code on my live server ^_^

Revert: OK