Add file splitter class

Simple class that will split a file in blocks of 128KB.
Change example file
Add function to get a block

It returns a vector of char (from offset, to offset + size).
Add structure for file analysis.

Add FileWatcherWorker (worker object) and FileWatcher (thread)

For now, all type of messages are emitted (newfile, modified file, delete file)
Add timer to run the worker every X secondes (10 here)

- set std::string as Qt Metatype
Detection of new/modified/deleted files

Add example folder : test/Sync

Watch folder every 30s
Check inode to detect overwritten files

Example:

t=0 : /x/file1 is copied to /sync/file1

t=1 : Modify /x/file1

t=2 : Scanning /sync/file1

t=3 : copy (overwrite) /x/file1 -> /sync/file2

t=4 : Scanning /sync/file1 => no changes detected because /sync/file1 has been modified when t=1 (before t=4)

Now we compare the inode to detect this kind of changes
Add scan period in XML config file

Add a tag to define the period (in secondes) between two scans of a folder.
Detect files in subfolders

+ add example in test/Sync
Add .shadappignore file detection and parsing to filter files/folders

Works the same way as .gitignore files
Merge branch 'feature-peerConnection' into develop
Merge branch 'develop' in 'feature-fileWatcher'
Merge branch 'feature-fileWatcher' into develop
Merge branch 'develop' into feature-peerConnection