sstate-cache-management.sh: Fix remove_duplicated() to work after SSTATE_SWSPEC change

* format of filenames for sstate archives was changed in:
  commit 6f823a23c5f1d0ffa0a27db1c1bc1907de788505
  Author: Richard Purdie <richard.purdie@linuxfoundation.org>
  Date:   Fri Dec 20 12:06:02 2013 +0000
  Subject: sstate: Convert to use ':' as a filename sperator and use SSTATE_SWSPEC globally
* remove_duplicated() wasn't able to find available architectures and
  duplicate files since this change
* add extra step to remove old sstate archives starting with sstate-
  (instead of sstate:)

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
sstate-cache-management.sh: Fix rm_by_stamps() to work after SSTATE_SWSPEC change

* format of filenames for sstate archives was changed in:
  commit 6f823a23c5f1d0ffa0a27db1c1bc1907de788505
  Author: Richard Purdie <richard.purdie@linuxfoundation.org>
  Date:   Fri Dec 20 12:06:02 2013 +0000
  Subject: sstate: Convert to use ':' as a filename sperator and use SSTATE_SWSPEC globally
* this one doesn't need special care for old sstate- names
  they will be removed automatically as they don't match with
  any checksum in rigth format from stamps directory

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
sstate-cache-management.sh: Show total number of files when showing how many will be deleted

* it's good to see some the ratio of delted files until now it was
  showing only when all or none files were to be removed

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
sstate-cache-management.sh: Fix available architectures

* grep for AVAILTUNES isn't enough in cases where AVAILTUNE doesn't
  match exactly with TUNE_PKGARCH, e.g. AVAILTUNE "cortexa8thf-neon"
  and TUNE_PKGARCH "cortexa8t2hf-vfp-neon", instead of trying to find
  dynamically every available TUNE_PKGARCH (we have _a lot_ of them
  even with oe-core only), add parameter --extra-archs where user can
  define extra architectures he supports in given build
* Don't replace '-' with '_' for extra-archs, it does apply to MACHINE
  names and some AVAILTUNES, but e.g. cortexa8thf-neon shouldn't be
  converted to cortexa8thf_neon
* Add empty architecture for populate_lic sstate archives
* Add ${build_arch}_${arch} combinations for toolchain recipes (e.g.
  gcc-cross is using x86_64_i586

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
sstate-cache-management.sh: don't remove all packagedata sstate archives

* packagedata task was introduced in:
  commit 6107ee294afde395e39d084c33e8e94013c625a9
  Author: Richard Purdie <richard.purdie@linuxfoundation.org>
  Date:   Wed Jan 23 14:27:33 2013 +0000
  Subject: Split do_packagedata task from do_package
* rm_by_stamps wasn't using do_packagedata or do_packagedata_setscene
  stamp files to find which sstate archives to keep, so it was removing
  all of them

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>