Implementing the rest of the log modes
Simplify modes
Implement log rotation, add convenience constructors
Add log message when rotating files
Revert "Revert "Added buffer to FileLogger""

This reverts commit f40e1151f237e848504e076166488618d69f4156.

Re-add buffering to filelogger so that it can be safely used in multi-threaded environments

Conflicts:
	filelog.go
Merge branch 'new-modes'

Conflicts:
	filelog.go