"ls" command now shows files more like in bash

1. "ls"    - symbolic links are now marked with different color
2. "ls -l" - showing correct rwx attributes for symbolic links
3. "ls -l" - showing path to the target file of symbolic links
4. "ls -l" - showing time in 24h format
5. "ls -l" - showing year when file was not modified in actual year
6. "ls -l" - user and group have now padding on right as in bash
7. "ls -a" - showing "." and ".." directories
Merge pull request #12 from rbalent/ls-improvements

"ls" command now shows files more like in bash
make sure that we're throwing interruptedexception correctly
needs to throw interruptedexception
[AESH-243]
initial popd and pushd implementation. works, but need more meat.
[AESH-243]
popd and push should work better now
version 0.55
0.56 dev cycle