Pyfaidx

- Spliced sequence retrieval 127 (Thanks simonvh)

- Removed BGZF warning (123) since the test suite contains good coverage of this feature.

- coordinates with start > end can be auto reverse complemented using `--auto-strand` argument (120)
- `--no-coords` flag in `faidx` script suppresses "sequence:start-end" in output sequence headers (121)
- `Sequence.long_name` is deprecated in favor of `Sequence.fancy_name`. `Sequence.longname()` is now removed from the codebase after previous DeprecationWarnings.

- Fixed issue in `key_function` validation logic

- Faster `faidx -i nucleotide` code

- Support for resolving duplicate keys using `duplicate_action` argument to `Fasta`
- Support for BGZF (block gzip compressed) FASTA files (77) (Thanks terrycojones!)
- Support for numpy 32bit and 64bit integer comparisons (114)
- Better file locking and buffer flushing (110)