Support compilation of OpenSlide 3.4.0

OpenSlide 3.4.0 requires sqlite3 for compilation; added support for this.  Build script tested and confirmed working with an Ubuntu 13.10 virtual machine running in VirtualBox 4.3.6.
Change ImageMagick to legacy directory

ImageMagick-6.8.7-10 is finally in the legacy/ directory, meaning no more having to mess with ImageMagick.org's silly update methods.
Merge pull request #5 from lightbinder/master

Adding support for OpenSlide 3.4.0 and fixing the ImageMagick update craziness forever