Clean up trailing whitespace throughout

This commit removes ^M and trailing whitespace from source files,
Makefiles, and readme files. The goal is to clean the code base so that
it is easier to create patches that don't contain whitespace changes.
This is useful for editors that automatically clean trailing whitespace
on save and to avoid seeing ^M's on mixed line ending mode files.
Fix "narrowing conversion" warning from g++.
Ignore example_apps outputs
Install app_loader library in system directories
prussdrv: add call to get file descriptor

This is needed to be able to select(2) or poll(2) on PRU interrupts.

Signed-off-by: Frank Hunleth <fhunleth@troodon-software.com>
Use 'install' instead of mkdir/cp/chmod
Merge pull request #14 from fhunleth/whitespace

Clean up trailing whitespace throughout
Merge pull request #15 from gburca/master

Fix "narrowing conversion" warning from g++.
Merge pull request #17 from fhunleth/selectfd

prussdrv: add call to get file descriptor