tools/cmake: update to 3.8.1

* update cmake to 3.8.1
* refresh patches

Release notes:
https://cmake.org/cmake/help/v3.8/release/3.8.html

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>

tools/cmake/patches/110-freebsd-compat.patch

@@ -21,10 +21,10 @@ Change-Id: I3b91ed7ac0e6878035aee202b3336c536cc6d2ff
 
 --- a/Source/kwsys/SystemInformation.cxx
 +++ b/Source/kwsys/SystemInformation.cxx
-@@ -89,6 +89,15 @@ typedef int siginfo_t;
- #  include <ifaddrs.h>
- #  define KWSYS_SYSTEMINFORMATION_IMPLEMENT_FQDN
- # endif
+@@ -82,6 +82,15 @@ typedef int siginfo_t;
+ #include <net/if.h>
+ #define KWSYS_SYSTEMINFORMATION_IMPLEMENT_FQDN
+ #endif
 +# if defined(KWSYS_SYSTEMINFORMATION_HAS_BACKTRACE)
 +#  include <execinfo.h>
 +#  if defined(KWSYS_SYSTEMINFORMATION_HAS_CPP_DEMANGLE)