The variables to set cachedir, rootdir and metadir have been
changed to "array of chars", this way there are no extra allocations.
Update clients accordingly and bump API version.
These are the core interfaces in the new API:
rpool - Interface to interact with the repository pool.
rindex - Interface to interact with repository indexes.
pkgdb - Interface to interact with local packages.
transaction - Interface to interact with a transaction.
This also brings new repository index format, making the index file
per architecture and being incompatible with previous versions.
The transaction frequency flush option has been removed, and due to
the nature of package states it was causing more harm than good.
More changes coming soon, but the API shall remain stable from now on.
