Merge pull request #54 from jairhenrique/master

Obrigado!
fixes #58
fixes multithreading random crashes
bumping version number
Merge branch 'master' of github.com:ricardocabral/iskdaemon
Revert "fixes multithreading random crashes". Will try locking on C++
This reverts commit 73b95c68619f2bdea033a77ffb923cb236d3ac29.
mutex lock for db operations
better documentation
fixes crash when searching after trying to insert image with duplicate id. Suggested by https://github.com/nicsor
fixed: addDir fails to import 4-char extensions

addDir now checks chars after the last '.' in the file name, instead of the last 3 chars. Without this, images with 4-character extensions (.jpeg, .tiff, ...) were skipped.
adding if necessary
reverting unnecessary mutex locks from b388849652
not necessary
bumping versin