bootstrap image: build needed source packages and add them

* IsPackageAvailable, FetchPackage: Add flags parameter. The only
  flag supported ATM is nameResolved, indicating that the specified
  package name does not need to be resolved with respect to a secondary
  architecture anymore.
* Add build profile action "build-package-list". As an argument the
  file to which the list of all packages needed for the image is
  written. The rule BuildHaikuImagePackageList implements the action.
* BuildBootstrapRepositoryConfig: Does now require the variable
  HAIKU_REPOSITORY_TREE_PATH to be set on the config file target instead
  of hard-coding the path. Allows reuse of the actions.
* Add rules BuildHaikuPortsSourcePackageDirectory and
  BuildHaikuPortsRepositoryConfig. The former builds all HaikuPorts
  source packages needed to build the packages for an alpha image. The
  latter generates a haikuports.conf file for use on the bootstrap
  Haiku.
* HaikuImageBootstrap: Add directory /boot/home/haikuports which
  contains a subdirectory with the source packages and a
  haikuports.conf.

build/jam/ImageRules

@@ -1035,6 +1035,32 @@ rule IsHaikuImagePackageAdded package
 }
 
 
+rule BuildHaikuImagePackageList target
+{
+	if ! $(target) {
+		return ;
+	}
+
+	# get the file names of all added packages
+	local packageFiles ;
+	local package ;
+	for package in $(HAIKU_ADDED_PACKAGES) {
+		packageFiles += [ FetchPackage $(package) : nameResolved ] ;
+	}
+
+	# extract the versioned package names (without revision)
+	packageFiles = [ Match "(.*)-[^-]*-[^-]*" : $(packageFiles:B) ] ;
+
+	HAIKU_IMAGE_PACKAGES on $(target) = $(packageFiles) ;
+}
+
+
+actions BuildHaikuImagePackageList
+{
+	echo $(HAIKU_IMAGE_PACKAGES) | xargs -n 1 echo | LC_ALL=C sort -u > $(1)
+}
+
+
 rule InstallSourceArchive file : url
 {
 	if $(HAIKU_INCLUDE_SOURCES) = 1 {