Merge pull request #43 from melmothx/feature/email-cids

Add code and documentation to support embedding images in emails
Add POD documentation on attributes for Pager class.
Bump up version number.
Prepare Changes and README files for upcoming release.
Requires the latest XML::Twig and adjust tests accordingly
Removed -T switch from regular tests
Merge pull request #44 from melmothx/topic/test-fix

Bump up prerequisite on XML::Twig to 3.48 and remove -T switch from regular tests.
Bump up version number.
Prepare Changes and README files for upcoming release.
Skip URI adjust for link elements without target attribute (<a href, <img src, ...).
Bump up version number.
Prepare Changes and README files for upcoming release.
Added failing test for value => undef
Fixed manifest
Consider undef <value> as empty string

This way, we remove the (placeholders) template values.

No tests break with this patch
Merge pull request #45 from melmothx/topic/fix-undef-values

Topic/fix undef values
Bump up version number.
Prepare Changes and README files for upcoming release.
Use iterator from specification instead of looking it up from template values.
Bump up version number.