Files server

Putting all the smallish files that are on files.opentreeoflife.org under version control.  Some were copied from gcmdr repo, some from the previous files.opentreeoflife.org incarnation on norbert, some are new. Deploy using './push.sh ... files' (documentation TBD). 

Rather than put the big files (OTT versions and synthetic trees) under version control, they're manually managed.
I'm a little uncomfortable with a hard-coded hostname here, since IIRC we haven't done this elsewhere. Since I'm installing the ```files``` component to the machine named ```$OPENTREE_HOST```, that seems like a reasonable default:
```
    if [ x$FILES_HOST = x ]; then FILES_HOST=$OPENTREE_HOST; fi
```
Thoughts?