Shorten wait for image to unmount when building mp3.img

git-svn-id: https://subversion.ews.illinois.edu/svn/sp14-ece391/_projects/group14/branches/terminal-driver@15538 1cec0ab5-dbbe-4d55-bb2a-e14ca091d7d0
Implement generic queue operations

git-svn-id: https://subversion.ews.illinois.edu/svn/sp14-ece391/_projects/group14/branches/terminal-driver@15539 1cec0ab5-dbbe-4d55-bb2a-e14ca091d7d0
Fix implementation of term_write so that it writes the number of bytes passed

git-svn-id: https://subversion.ews.illinois.edu/svn/sp14-ece391/_projects/group14/branches/terminal-driver@15540 1cec0ab5-dbbe-4d55-bb2a-e14ca091d7d0
Refactor keyboard driver to use generic queue operations

git-svn-id: https://subversion.ews.illinois.edu/svn/sp14-ece391/_projects/group14/branches/terminal-driver@15541 1cec0ab5-dbbe-4d55-bb2a-e14ca091d7d0