Avalanche 2.1

Changes in this version:

• New browser mode, removed old hierarchical browser.
• Select/Clear/Invert selection now act on the current directory and
  all subdirectories when in the new browser mode.
• Basic editing of (LhA, Zip) archives (Zip needs zip.library - OS4 only)
• Create new (LhA, Zip) archives

Full Changelog: v1.11...v2.1