Don't remove CDATA sections from templates

[s2b]

The removal of all CDATA sections was introduced with 978071f without any clear indication why this was done. The consequence now is that there is no longer a "parser stop marker", for example for inline CSS interfering with Fluid's inline syntax.

Later, this was documented as a "solution" to hide invalid Fluid syntax from the Fluid parser, for example during development. Since <f:comment> now works correctly for invalid Fluid, we should consider not removing CDATA sections from templates anymore.