Lastpage (and hyperref) package compatibility fix

[kgeorgiy]

Disables a lastpage compatibility shim when the actual lastpage package is present.

This change seems to be useless per se, but the lastpage package, in turn, provides compatibility shims for other packages, such as hyperref, thus allowing their usage.

Both lastpage and hyperref usage examples added. Feel free to move them to the appropriate place, if any.