2. Add jt9code.exe to the Windows installation file.
3. Changed hotkey for "Special Mouse Commands" to F5, so that F4 again works
as it did.
4. Several corrections to shortcuts.txt.
5. Added section "Under the Hood" to the User's Guide.
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@3254 ab8295b8-cf94-4d9e-aec4-7959e3be5d79