Deleted acute_rx.md; no longer needed to be tracked
Changed page names and updated links. Placeholders for new categories of acute reactions.
Updated Diffuse Erythema section
Updated Bronchospasm and Hives sections
Updated Laryngeal Edema section
Updated Hypotension with Bradycardia section
Updated Hypotension with Tachycardia section
Merge branch 'ver9_2013' of https://github.com/dskrad/contrastrx into ver9_2013