Resolved issue that with nested () that was introduced by last commit

PlumedToHTML/PlumedLexer.py

@@ -28,8 +28,6 @@ class PlumedLexer(RegexLexer):
             (r'(\w+)(=)(@\S+:)(\S+\b)', bygroups(Name.Attribute, Text, Name.Constant, Generic)),
             # Find KEYWORD with {} brackets around value
             (r'(\w+)(=)((?s)\{.*?\})', bygroups(Name.Attribute, Text, Generic)),
-            # Find KEYWORD with () brackets around value 
-            (r'(\w+)(=)((?s)\(.*?\))', bygroups(Name.Attribute, Text, Generic)),
             # Find KEYWORD=whatever 
             (r'(\w+)(=)(\S+\b)', bygroups(Name.Attribute, Text, Generic))
          ],

setup.py

@@ -6,7 +6,7 @@
 
 setuptools.setup(
      name='PlumedToHTML',  
-     version='0.72',
+     version='0.73',
      author="Gareth Tribello",
      author_email="[email protected]",
      description="A package for creating pretified HTML for PLUMED files",

tdata/lexertests.json

@@ -81,8 +81,12 @@
          "output": "<div class=\"highlight\"><pre><span></span><span class=\"c\"># This is a comment </span>\n <span class=\"s\">phi</span>: <span class=\"k\">TORSION</span> <span class=\"na\">ATOMS</span>=<span class=\"g\">1,2,3,4</span> <span class=\"c\"># This is also a comment with : a colon</span>\n</pre></div>\n"
        },
        {
-         "input": "st_saxs: STATS ARG=(SAXS\\.q-.*) PARARG=(SAXS\\.exp-.*)",
-         "output": "<div class=\"highlight\"><pre><span></span><span class=\"s\">st_saxs</span>: <span class=\"k\">STATS</span> <span class=\"na\">ARG</span>=<span class=\"g\">(SAXS\\.q-.*)</span> <span class=\"na\">PARARG</span>=<span class=\"g\">(SAXS\\.exp-.*)</span>\n</pre></div>\n"
+        "input": "a: CUSTOM ARG=x PERIODIC=NO FUNC=(step(x-1))",
+        "output": "<div class=\"highlight\"><pre><span></span><span class=\"s\">a</span>: <span class=\"k\">CUSTOM</span> <span class=\"na\">ARG</span>=<span class=\"g\">x</span> <span class=\"na\">PERIODIC</span>=<span class=\"g\">NO</span> <span class=\"na\">FUNC</span>=<span class=\"g\">(step(x-1</span><span class=\"err\">))</span>\n</pre></div>\n"
+       },
+       {
+         "input": "st_saxs: STATS ARG={SAXS\\.q-.*} PARARG={SAXS\\.exp-.*}",
+         "output": "<div class=\"highlight\"><pre><span></span><span class=\"s\">st_saxs</span>: <span class=\"k\">STATS</span> <span class=\"na\">ARG</span>=<span class=\"g\">{SAXS\\.q-.*}</span> <span class=\"na\">PARARG</span>=<span class=\"g\">{SAXS\\.exp-.*}</span>\n</pre></div>\n"
        }
    ]
 }