Detect and use -Weffc++
Detect and use -Weffc++

I just discovered the -Weffc++ warning flag and the checks performed by
this seem very useful (based on the book they relate to).  Enable it if
the compiler supports it; doesn't raise any problems in OS X.

This change was r266 in Subversion.

jmmv/kyua,jmmv/kyua,rodrigc/kyua,rodrigc/kyua,jmmv/kyua,rodrigc/kyua,jmmv/kyua,rodrigc/kyua