Added .hpp headers from OpenCL-CLHPP release 2.0.9
Tried to future-proof things slightly.
Use github to obtain the header files in a .ZIP file so we do not need
to update the checksums for the zip file each time it was regenerated.
remove mksource because that's no longer needed.
* upgrade some broken packages
* correct some broken urls/checksums
* use secure urls where possible
* update PKGBUILD templates
* remove line-ending whitespace
* minor typos/fixes
Remaining md5sums either didn't download or
didn't pass checksum tests.
