BLOCKER: Allow multiple templates per raw data

Multiple fixes in the PR:
- Allows multiple prep templates per raw data
- Preprocessed data is now linked with prep template rather than raw data
- Fixes #326 
- Changes on initialize.sql:
  - SPECTRA removed
  - SFF added
  - FASTA -> FASTA-Sanger

This PR allows @antgonza to continue with his PR.
I got the error below at first, but when I added `--prep_template_id` that error went away:

```bash
(qiita)yoshikivazquezbaeza:new_usable_files$ qiita db load_preprocessed --study_id 10000 --params_table preprocessed_sequence_454_params --filedir temp/ --filepathtype preprocessed_fasta --params_id 1 
Traceback (most recent call last):
  File "/Users/yoshikivazquezbaeza/git_sw/qiita/scripts/qiita", line 226, in <module>
    qiita()
  File "/Users/yoshikivazquezbaeza/.virtualenvs/qiita/lib/python2.7/site-packages/click/core.py", line 384, in __call__
    return self.main(*args, **kwargs)
  File "/Users/yoshikivazquezbaeza/.virtualenvs/qiita/lib/python2.7/site-packages/click/core.py", line 370, in main
    self.invoke(ctx)
  File "/Users/yoshikivazquezbaeza/.virtualenvs/qiita/lib/python2.7/site-packages/click/core.py", line 614, in invoke
    return self.invoke_subcommand(ctx, cmd, cmd_name, ctx.args[1:])
  File "/Users/yoshikivazquezbaeza/.virtualenvs/qiita/lib/python2.7/site-packages/click/core.py", line 623, in invoke_subcommand
    return cmd.invoke(cmd_ctx)
  File "/Users/yoshikivazquezbaeza/.virtualenvs/qiita/lib/python2.7/site-packages/click/core.py", line 614, in invoke
    return self.invoke_subcommand(ctx, cmd, cmd_name, ctx.args[1:])
  File "/Users/yoshikivazquezbaeza/.virtualenvs/qiita/lib/python2.7/site-packages/click/core.py", line 623, in invoke_subcommand
    return cmd.invoke(cmd_ctx)
  File "/Users/yoshikivazquezbaeza/.virtualenvs/qiita/lib/python2.7/site-packages/click/core.py", line 524, in invoke
    ctx.invoke(self.callback, **ctx.params)
  File "/Users/yoshikivazquezbaeza/.virtualenvs/qiita/lib/python2.7/site-packages/click/core.py", line 236, in invoke
    return callback(*args, **kwargs)
  File "/Users/yoshikivazquezbaeza/git_sw/qiita/scripts/qiita", line 122, in load_preprocessed
    prep_template_id)
  File "/Users/yoshikivazquezbaeza/git_sw/qiita/qiita_db/commands.py", line 119, in load_preprocessed_data_from_cmd
    submitted_to_insdc_status=submitted_to_insdc_status)
  File "/Users/yoshikivazquezbaeza/git_sw/qiita/qiita_db/data.py", line 451, in create
    raise IncompetentQiitaDeveloperError("Neither data_type nor "
qiita_core.exceptions.IncompetentQiitaDeveloperError: Neither data_type nor prep_template passed!
```