Version 0.2-alpha1

Main changes/improvements in this release (still work in progress, though):

• “silent” mode. It is now possible to control the output from the script in a slightly more fine-grained way: while the pre-existing “non-interactive” mode suppresses any message sent to standard output, “silent” mode also suppresses messages sent to standard error;
• Improved “debug” mode: enabling it is now the same as
  • enabling interactive mode (and disabling silent mode)
  • enabling assertions
  • enabling style
  • setting log threshold to debug level, and printing log entries to stderr;
• EXIT pseudo-signal handling: this allows script to register one or more functions that should be executed before exiting, e.g. cleanup code that removes temporary files, locks, and so on;
• created a simple API to manage messages about the execution of the script: now bib.warn() and bib.error() are defined for printing state information about the script. They serve as the basis for more advanced features that I am working on, such as deprecation warnings and signal trapping.

Full Changelog: 0.1.1...0.2-alpha1