efreet - save about 240-300k or so of memory used by efreet mime

efreet - save about 240-300k or so of memory used by efreet mime

so efreet mime was loading a bunch of mime type info files, parsing
them on startup and allocating memory to store all this mime info -
globs, mimetype strings and more. all a big waste of memory as its
allocated on the heap per process where its the SAME data files loaded
every time.

so make an efreet mime cache file and a tool to create it from mime
files. mmap this file with all the hashes/strings in it so all that
data is mmaped once in memory and shared between all processes and it
is only paged in on demand - as actually read/needed so if your
process doesnt need to know about mime stuff.. it wont touch it anyway.

this saves about 240-300k or so of memory in my tests. this has not
covered the mime MAGIC files which still consume memory and are on the
heap. this is more complex so it will take more time to come up with a
nice file format for the data that is nicely mmaped etc.

@optimize