trace 4.7.x-1.0

The initial stable version for Drupal 4.7.x.

Changes since the previous development snapshots:

• Removed Drush stubs, as they are unlikely to be further fleshed out.
• #127645: Added information to README.txt regarding manual trace toggling using MySQL; updated TODO.txt to reflect the current status of the module.
• #171465: Added a sanity check to _trace_format_function_call() argument handling.
• Implemented a new None output driver, useful for allowing third-party extension modules take over logging responsibilities.
• Removed the hardcoding of LOG_NOTICE from the Syslog output driver.
• Amended the default settings for excluded pages to take into account 404 Not Found requests of favicon.ico.
• Disabled the watchdog tracing settings for the moment, as they have not yet been implemented.
• Implemented a new setting for determining whether to output page request start/stop times, allowing less noisy log files in production environments.
• Also log the explicit time duration for SQL queries, in addition to the (estimated) time delta from the start of the page request.