disable fnmatch()

The current PackageContainerInterface::FromString() will do a
FromFnmatch() first and then FromRegEx(). This commit reverts
that change to restore the old behavior to only look for RegEx
and not glob-style pattern. The rational is that:
a) currently a fnmatch() is misleadingly reported as a regex match to
   the user (Bug#738880)
b) a fnmatch may match something different than a a RegEx so the
   change broke a published interface

apt-pkg/cacheset.cc

@@ -312,7 +312,6 @@ bool PackageContainerInterface::FromString(PackageContainerInterface * const pci
 
 	if (FromGroup(pci, Cache, str, helper) == false &&
 		 FromTask(pci, Cache, str, helper) == false &&
-		 FromFnmatch(pci, Cache, str, helper) == false &&
 		 FromRegEx(pci, Cache, str, helper) == false)
 	{
 		helper.canNotFindPackage(pci, Cache, str);