Fix for " setup_msgs causes a section type conflict with __c"

Fix for " setup_msgs causes a section type conflict with __c". I just bought a BLE Shield 2. The library would not compile using Arduino 1.0.5. The same issue was documented in this forum entry:
https://redbearlab.zendesk.com/entries/23440476-Getting-Started

In the latest version of Arduino, the new avr gcc requires that PROGMEM use include the const modifier. This causes a section type conflict error as reported by some users of the shield. As a result, I couldn't get this shield working with my Arduino Duemilanove without this change. Full documentation on what fixed the error can be found here: http://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&t=38003.