Speed-up boot time with fcache

Fcache is a module to reduce boot time by linearizing access to files. In "prime mode" files are appended to the cache. In "normal mode" files are looked up in cache first which will generally imply linear access thus reducing seek times. Speed improvements of 33% have been reported. Gains are particularly evident when you need to start processes that require access to several files that are scattered over the partition implying high seek times. Its use should be investigated.