Market & Book Search

-Market Search fixes & optimization
Can now search for substrings of courses
Regexps corrected to accomodate search strings better
WhereClauses for several SQL Selects optimized to cover wider range of
inputs
IsBuy now incorporated to retrieve appropriate market posts
-Textbook Search Implementation for Add New Posting page
Created separate partial view for rendering the "li" elements of the
Textbook Search
-Both searches changed from delay per user input to making ajax call per
key input and aborting any previous (existing) ajax calls