Experimental support for "property name interpolation".

test/css/property-name-interp.css

@@ -0,0 +1,14 @@
+test {
+  border: 0;
+  ufo-width: 50%;
+  *-z-border: 1px dashed blue;
+  -www-border-top: 2px;
+  radius-is-not-a-border: true;
+  border-top-left-radius: 2em;
+  border-top-red-radius-: 3pt;
+  global-local-mixer-property: strong;
+}
+test-merge {
+  pre-property-ish: high, middle, low, base;
+  pre-property-ish+: nice try dude;
+}

test/less/errors/property-asterisk-only-name.less

@@ -0,0 +1,3 @@
+a {
+    * : 1;
+}

test/less/errors/property-asterisk-only-name.txt

@@ -0,0 +1,4 @@
+ParseError: Unrecognised input in {path}property-asterisk-only-name.less on line 2, column 5:
+1 a {
+2     * : 1;
+3 }

test/less/errors/property-interp-not-defined.less

@@ -0,0 +1 @@
+a {outline-@{color}: green}

test/less/errors/property-interp-not-defined.txt

@@ -0,0 +1,2 @@
+NameError: variable @color is undefined in {path}property-interp-not-defined.less on line 1, column 12:
+1 a {outline-@{color}: green}

test/less/property-name-interp.less

@@ -0,0 +1,41 @@
+
+test {
+    @prefix: ufo-;
+    @a:    border;
+    @bb:      top;
+    @c_c:    left;
+    @d-d4: radius;
+    @-:         -;
+    
+    @{a}: 0;
+    @{prefix}width: 50%;
+    *-z-@{a} :1px dashed blue;
+    -www-@{a}-@{bb}: 2px;
+    @{d-d4}-is-not-a-@{a}:true;
+    @{a}-@{bb}-@{c_c}-@{d-d4}       : 2em;
+    @{a}@{-}@{bb}@{-}red@{-}@{d-d4}-: 3pt;
+
+    .mixin(mixer);
+    .merge(ish, base);
+}
+
+@global: global;
+
+.mixin(@arg) {
+    @local: local;
+    @{global}-@{local}-@{arg}-property: strong;
+}
+
+.merge(@p, @v) {
+    &-merge {
+        @prefix: pre;
+        @suffix: ish;
+        @{prefix}-property-ish+       :high;
+        pre-property-@{suffix}    +: middle;
+        @{prefix}-property-@{suffix}+:  low;
+        @{prefix}-property-@{p}   +  :   @v;
+    
+        @subterfuge: ~'+';
+        pre-property-ish@{subterfuge}: nice try dude;
+    }
+}