Shogun's Progress Bar

Shogun's Progress Bar

1) Base features:
- UTF-8/ASCII progress bar mode switch (prevents Windows madness);
- Display current SG_PROGRESS information (maybe others like iterations/second);
- Three range types: 
	-> prange(0, 100): range with bound; 
	-> prange(100): range with upper bound;
	-> prange(it.begin(), it.end()): range using an iterators (range over a custom set of values);
	-> prange_mt(100): range multi-threaded;

2) Possible other features:
- Add a "pretty" print mode;
- Specify the char used for the progress bar;
- Resizable progress bar (since only \n and \r will be used the user can blow things up by changing the terminal size);

3) Example (future) usage:

for (auto i : prange(0, 100)) {
 /* Do stuff */
}

for (auto i : prange(0, 100, "pretty")) {
 /* Do fancier stuff */
}