Merge pull request #282 from laf/api

Initial API release; note it is marked v0 - not guaranteed stable until v1 is reached.
SNMP passwords are now hidden on an edit snmp form
Merge pull request #290 from laf/issue-laf-39

SNMP passwords are now hidden on an edit snmp form
Make API docs match current state of API
Don't exclude plugins from git
Minor tweaks to footer to show we're our own project now. :-)
Supply more specific error code when API token is missing or invalid
Increase API token length to allow for future growth
Provide more useful diagnostics when adding a device via the API
Add function to get information about a single device
Order devices by API entry point
Tidy device deletion
Re-implement get_device using existing primitives
Use more accurate HTTP status code for device add
Remove obsolete function (already provided by getidbyname)
keep scrutinizer from complaining about snmpver not being set for all execution paths
Correctly set error code for missing SNMP version
Rewrite ugly if-else one-liners as ternary operator
Fix Scrutinizer errors
Revert "Don't exclude plugins from git"

This reverts commit a38b2f37c2a99a959edf0aa145e11be3409a5e9e.