[fix] dont crash without a callback in update
Merge remote-tracking branch 'upstream/master'
 * [test] test cases for #108
 * [fix] don't expose _id,_rev,resource on safeJSON
Resource specific engine patch

just a switch
Added more documentation links.
Merge pull request #135 from xjamundx/patch-1

Added more documentation links.
Merge pull request #114 from chbm/safejson

fix safeJSON
Merge pull request #131 from jkroso/master

engine priority
[fix] fix uncaught error when a view does not return `rows`.
Merge pull request #137 from flatiron/fix_rows_error

[fix] fix uncaught error when a view does not return `rows`.