libcaca: blacklist clang < 900

- Necessary to fix builds for 10.8 and 10.9
- Also fix lint warnings, related to tab use, on lines 101 and 117

graphics/libcaca/Portfile

@@ -2,6 +2,7 @@
 
 PortSystem          1.0
 PortGroup           github 1.0
+PortGroup           compiler_blacklist_versions 1.0
 
 name                libcaca
 categories          graphics
@@ -63,6 +64,9 @@ use_autoconf         yes
 depends_build-append port:libtool port:autoconf port:automake
 autoconf.cmd         ./bootstrap
 
+compiler.blacklist-append \
+                    {clang < 900}
+
 # require C++11 for CppUnit API
 compiler.cxx_standard   2011
 configure.cxxflags-append -std=gnu++11
@@ -94,7 +98,7 @@ configure.args-append \
 # Disable silent rules
 build.args-append   V=1
 
-variant	x11 {
+variant x11 {
     depends_lib-append \
         port:imlib2 \
         port:freeglut \
@@ -110,7 +114,7 @@ if {[variant_isset x11]} {
         --x-includes=${prefix}/include \
         --x-libraries=${prefix}/lib
 } else {
-	configure.args-append \
+    configure.args-append \
         --disable-x11 \
         --disable-gl \
         --disable-imlib2