birthdays 5.x-1.2

New version, probably the last 5.x-1.x version before starting with Birthdays 5.x-2.x.

See new documentation in README.txt or at http://drupal.org/node/315658

Major changes:

• Date field can now be empty and thus truly be required. Defaults to empty, to make accidental birthdays less likely.
• Dropped 'delete birthday' permission and 'Remove birthday' check box. (Mark profile field as Required or not to get the same behavior)
• Frequency of admin mails is now configurable (daily, weekly, monthly).

Minor improvements

• Added the use of hook_requirements() and made requirement checks less intrusive but more informative.
• Added option 'hide block when no birthdays' in stead of showing the 'Nobody is having their birthday soon'.
• Fixed bug in cron execution which caused it to creep forward over time.

Coding improvements

• Introduced constants in stead of hard coded values.
• CHANGELOG.txt, INSTALL.txt and README.txt are now similar to Drupal's files
• Birthdays field is set as global during module initiation in stead of using the 'birthdays_field_name' variable all over the place.
• Fixed various small issues and cleaned up code.