added option to read sizes from a pregenerated file rather than indexing the filesystem itself; this covers cases of special file systems that cannot be index using a standard POSIX interface and allow using more efficient indexing tools
adding a new --auto option for the --read indexing and complete the README instructions
enable the possiblity to set the timestamp from the commandline when generating the database or for a complete database
move the timestamp output a little bit down to avoid collisions
better control over which files can be accessed as a database
security fix
considering DB used when caching images
never break file sizes, even when file names get too long
Updates to support gem `bdb` and `cairo` dependencies and ruby 1.9+.

Updating database access to reflect current bdb API and updating readme
to reflect updated dependencies.