xbps-src: infrastructure changes required for "nonfree" keyword in tmpls.

- The chroot target now execs masterdir/bin/xbps-shell to set up correct envvars.
- 2 pkgs are now in nonfree repo: adobe-flash-plugin and jre.
- Renamed some vars in xbps-src to be in uppercase, notably XBPS_MACHINE.
- make-repoidx target now creates the index for all "known" directories specified
  via XBPS_PACKAGESDIR: XBPS_MACHINE, noarch, and nonfree/XBPS_MACHINE.

srcpkgs/adobe-flash-plugin/template

@@ -5,7 +5,7 @@ revision=1
 # The EULA file
 _eula="http://www.adobe.com/products/eulas/pdfs/PlatformClients_PC_WWEULA_Combined_20100108_1657.pdf"
 _eulacksum=3cb0a5f4576be735abcff7189ed18eda17c70b762c3a78a3379b6f44395fbc10
-if [ "$xbps_machine" = "x86_64" ]; then
+if [ "$XBPS_MACHINE" = "x86_64" ]; then
 	# There is no x86_64 version for 10.1beta yet.
 	_disttarball="http://fpdownload.macromedia.com/get/flashplayer/current/install_flash_player_11_linux.x86_64.tar.gz"
 	_distcksum=5756a4ac9811e0362da2b0c208a458b417883e9f9c3773c70e61c935609b64dc
@@ -21,6 +21,7 @@ maintainer="Juan RP <xtraeme@gmail.com>"
 long_desc="
  This is the Adobe Flash Player plugin for Netscape compatible browsers."
 
+nonfree=yes # restricted use
 gtk_iconcache_dirs="/usr/share/icons/hicolor"
 
 Add_dependency run libgcc