Bug fixes

3faa78d Issue #2983910 by attilatilman: Error when saving a template mapping drupal 7
b7c6f0b Issue #2913620 by xlin: Handle plain text field
e06a17e Issue #2867845 by xlin: Import file attachment failed if file field is empty

This release contains the following bugfixes and features:
a509f3b Issue #2983849 by attilatilman: Error when saving a template mapping
27ace11 Issue #2977162 by Kova101: Supporting multiple GC field mapping to a single Drupal field with concatenation
5a44be5 Issue #2977159 by Kova101: Remove the upload module, because the API's next release won't support it
9d703a4 Issue #2948437 by Kova101: Exceeded max_input_vars for a single item
8a88e9f Issue #2856274 by Kova101, weri: Allow the selection of the text format to use for rich text fields

Development release.

This branch (3.x) MUST be used in conjuction with Registry on steroids.

Updated security. Added basic authentication.

Fixed a small problem with an improper php opening tag.