Replacing filegetcontents

file_get_contents for URLs is considered harmful, and is often disabled. This patch unifies file_get_contents($url) with the internal web services class, so:

1) This function will work in hosted environments where fopen protocol wrappers are disabled for security (irritatingly common)

2) It obeys our global curl settings, so for example sends a nice browser id string, and in future will obey proxy settings etc (refs: #202)