Remove MONGOOSE_NO_DAV on DAV_AUTH_FILE options

Building with -DMONGOOSE_NO_DAV will fail.
Tyop fix.
Merge pull request #351 from da4089/master

Tyop fix.
Merge pull request #350 from solomonhuang/nodav

Remove MONGOOSE_NO_DAV on DAV_AUTH_FILE options
updated faw and tutorials
I think that the socket is invalid, the return should be -1.
Merge pull request #352 from ranzhengyuan/some-idea

I think that when the socket invalid, the return value should be -1.
changed set_absolute_path() signature
Added mg_load_dll()
Merge branch 'master' of ssh://github.com/valenok/mongoose
Added release notes
Moving lua server side to server.c
Fix #356
Added release note
match_prefix -> mg_match_prefix
Restored void * parameter for iterate_over_connections()
changed handle_propfind() to report only dir entry when listing dir
Added hexdump_file option
FileSharing doc nitpick
Better API documentation