Fix gcc2 and ICU optional packages

* InstallOptionalHaikuImagePackage: In case of hpkg packages, copy them
  to the target directory, instead of extracting them.
* Correct gcc 2 package download URL.
* The ICU gcc 2 optional packages has been repackaged as hpkg. Use that.
  For gcc 4 things are broken, now.

build/jam/OptionalPackages

@@ -86,6 +86,7 @@
 #	Yasm					- the assembler utility
 
 local baseURL = http://haiku-files.org/files/optional-packages ;
+local hpkgBaseURL = http://haiku-files.org/files/hpkg ;
 local baseSourceURL = http://haiku-files.org/files/sources ;
 
 # ABI-compliance-checker
@@ -515,7 +516,7 @@ if [ IsOptionalHaikuImagePackageAdded DevelopmentBase ]
 	# gcc and binutils
 	if $(HAIKU_GCC_VERSION[1]) = 2 {
 		InstallCommonPackage gcc-2.95.3_110304-1.hpkg
-			: $(baseURL)/gcc-2.95.3_110304.hpkg ;
+			: $(hpkgBaseURL)/gcc-2.95.3_110304-1.hpkg ;
 
 		# TODO: remove this when we have a mechanism to switch gcc via PATH
 		AddSymlinkToHaikuImage common settings develop tools
@@ -856,8 +857,8 @@ if [ IsOptionalHaikuImagePackageAdded ICU ] {
 		if $(HAIKU_GCC_VERSION[1]) = 2 {
 			# unzip gcc2
 			InstallOptionalHaikuImagePackage $(HAIKU_ICU_GCC_2_PACKAGE)
-				: $(baseURL)/$(HAIKU_ICU_GCC_2_PACKAGE)
-				: system lib ;
+				: $(hpkgBaseURL)/$(HAIKU_ICU_GCC_2_PACKAGE)
+				: system packages ;
 		} else {
 			# unzip gcc4
 			InstallOptionalHaikuImagePackage $(HAIKU_ICU_GCC_4_PACKAGE)