Added support for preferring html content over text content.
Added support for storing html content in addition to text content.
Ignore prefer_html_content flag when with_html_content flag is true and check prefer_html_content flag when setting the textContent field since user may wish to store html in the textContent field and not as a separate field.
Fixed issue that prevent multiple imap rivers from being scheduled at the same time due to existing trigger with name: 'intervaltrigger' and group: 'group1'
testcases for attachment mapping added
Merge branch 'master' of https://github.com/mscifo/elasticsearch-river-imap into mscifo-master
Merge branch 'mscifo-master'