Fixes #372

Before attempting to send mail, the hostname is retrieved using
socket.gethostname. If the hostname includes 'microbio.me', then mail is sent.
Otherwise, the user is dumped back to the portal with a message stating that
mail can be sent only from the microbio.me domain.
Merge branch 'master' of https://github.com/qiime/qiime_web_app into i372
Add function can_send_mail

takes no arguments, returns true if 'microbio.me' is in socket.hostname();
returns false otherwise
Adding doc string and streamlined fn
Modify files to use can_send_mail

Files should use can_send_mail from utils.mail instead of explicitly checking
whether or not 'microbio.me' appears in socket.hostname() return value
Merge branch 'master' of https://github.com/qiime/qiime_web_app into i372

Conflicts:
	www/americangut/submit_human_survey.psp
Merge branch 'master' of https://github.com/qiime/qiime_web_app
Add Tito Jankowski's how-to in survey info

Linking to Tito's How-To guide in the survey information that we have in
the step by step guide.
Merge branch 'master' of https://github.com/qiime/qiime_web_app
Fix ag_delete_participant

Fixes #505. This fix touches SQL code. ag_delete_participant now does not
remove samples, instead only removing logs and survey data. If samples also
need to be removed, that will have to be done separately.
Modify files that used ag_delete_participant

Added logic to remove samples only in places where it's needed to do so. Also
cleaned up some tabs/spaces heterogeneity in submit_human_survey.psp
Add squash_barcodes.py

This script (originally written by Daniel) is used to create a single
printable PDF from a collection of barcode images.
Merge pull request #501 from ElDeveloper/link

Add Tito Jankowski's how-to in survey info.
Fix formatting of vvalues to str
Merge pull request #518 from adamrp/fix_ebi

Fix formatting of vvalues to str
Add flush of output buffers for logging
Merge pull request #520 from adamrp/rest_data_logger

Add flush of output buffers for logging
Merge branch 'master' of git://github.com/qiime/qiime_web_app into barcode2
Add round4 barcodes to metadata select query
Adding Rob Steins resequenced barcodes