4.6.5: nmh 1.8 support

• nmh 1.8 support (changes to unit tests only)

4.6.4: improved IMAP support

• Set window type to Notification so it doesn't steal the focus on popup.
• Expand internal buffer to handle multi-byte characters.
• Option -debug now takes a debug level.
• Handle unquoted literals in bodystructure response from IMAP server.
• Handle non-fuzzy preview from recent IMAP servers.
• Handle folded Subject lines.

4.6.3: disable automatic tests of window behavior

• Developers: Disable automatic runs of flaky windowing test.
  Test was introduced in version 4.5.4.

4.6.2: more robust test utilities

• Developers: Tests do not write soft failures to stderr

4.6.1: Maildir support

• Maildir format for local mailbox is supported by mailbox-preview.
• mailbox-preview has other minor improvements.
• Developers: Tests fixed to work without a merged /usr partition.

4.6: IMAP support

• mailbox-preview: new script to support IMAP
• scanCommand accepts a "rows" parameter with additional %d
• xlbiff.form moved to nmh's config directory and used by default

4.5.6: more robust test utilities

Developers: Tests use Xvfb directly, eliminating xvfb-run script.

4.5.5: xlbiff.form does decode

• xlbiff.form decodes RFC 2047 (MIME-encoded) "From" and "Subject" headers
• Developers: Fix three timing races in windowing test.

4.5.4: tests of window behavior

• Developers: Add tests of the window behavior of Popup and Popdown

4.5.3: window behavior fixes

• Window no longer moves with -bottom and a window manager running
  when mailerCommand does not change the mailbox
• Refresh time is now honored and -ledPopdown works with -bottom
• mailer() action always re-checks for mail, even with no mailerCommand
• Intervals can be floating point: -update, -fade, and -refresh
• Null-terminate message scan output (error found by Coverity Scan)
• HISTORY file renamed to NEWS