Add ICAL_CHECK_VERSION macro

[Allen Winter]

On Wednesday, January 20, 2016 10:00:05 PM Milan Crha wrote:
> 	Hello,
> looking into the icalversion.h.cmake, it's not that useful to have the
> version defined as a string. To be honest, I do not know whether it can
> be used for conditional compiles.
agreed.

> 
> Due to that, it would be handy to introduce a version check macro like
> some other libraries do. I would name it:
>    ICAL_CHECK_VERSION(major,minor,micro)
> You can copy&paste most of the things from gtk+, for example:
> https://git.gnome.org/browse/gtk+/tree/gtk/gtkversion.h.in
> thus it would be pretty simple to do.
Good idea. I will implement this.

> 
> I also noticed that pkg-config returns only major.minor and ignores
> micro, similar with the ICAL_VERSION from icalversion.h. Is it
> intentional? Why to hide the micro version?
> 
Not intentional.
Fixed in commit cdc85e9e7a14932808471f823bc974031a0c4842