script must export LC_ALL=C to make sure the 'error' is echoed
correctly. Another thing is if there is a download error due to
proxy or firewall settings on the system. It should exit immediately
with a proper error message.

BUG: MANTIS-1112 (File not found if filename contains accents when using GUI) Replaced QString::toAscii() by QFile::encodeName() when converting filenames to std::string and used QFile::decodeName() when converting std::string filenames to QString ones.

itkStaticConstMacro has some modification in ITK 4.9+
as a result of VLV performance enhancements. This gives
link errors in 3rdParty trunk which use ITK 4.9. Using
enum directly gives more clarity and was an easy fix.

This reverts commit f72c58b7.