Use firstliney method to retrieve first line for a resource
Don't create new resource objects when passing them to filters

NOTE: This change is highly experimental; it *should* work just fine,
but there might be some weirdness that isn't picked up in the test
suite.
Lazily open basic resources

This causes a problem with file permission detection; I'll fix this
later
Optimization (faster to check flag).

Checking a flag for opening is a lot faster than checking if the
filehandle is defined. Speeds up nytprof target from 7.05s to 4.89s.
Use --noenv for timer targets
Access resource filehandles directly
Fix line endings on output
Make sure we return falsy if open fails
Check for bad filehandle opening
Make sure we mark a resource around STDIN as already open
Report unreadable filehandles
Remove _lazily_open
Remove next_text()
Add docs/stub for open