Making command line arguments for our cmake files to be case insensitive

[PrasadBabarendaGamage]

Might be best to make the -DOpenCMISSLibs_DIR case insensitive so its easier for users.

[nickerso]

Consistent case would be beneficial, but in CMake-land variables are always case-sensitive (pretty sure) and it would be crazy to try and add our own functionality to achieve that. Documentation is more than sufficient to make user's lives easier.

[hsorby]

I think also that because every example that creates an executable target needs to have the variable set then every example would also have to have the mechanism for managing the case insensitive variable present. This would then need to apply to any other variables set in the command line and would be going against the nature of the scripting language.

Clear documentation should mitigate this issue.

[chrispbradley]

The variable is, at the very least, inconsistent with all the other cmake variables used. Most of these OpenCMISS variables are of the form OPENCMISS_XXX. In addition other variables used for identifying locations in file systems are called ROOT e.g., OPENCMISS_ROOT. A more consistent variable name would be OPENCMISS_INSTALL_ROOT?