updating insert script for tenants table
Update README.md

and update links to community and demo app
Update README.md

and strike out the reference app link
Update CHANGELOG.md

for 1.21.0 RELEASE
bump up the release number to 1.21.0
Update README.md

with links to API docs
Update INSTALL.md

with instructions for those upgrading an existing Mifosx installation to version 1.21.* or higher
Update INSTALL.md

move reference to database updates to section  2.2.2
fix insert script for mifosplatform-tenants database
update the readme for community apps
fixing typos in install.md
Update README.md

with minor edits