Add support for newdmd (bug 717853).

If b2g.sh sees /system/bin/libdmd.so exists, it concludes we're using newdmd and passes appropriate parameters to the B2G process.

If default-gecko-config sees the MOZ_DMD variable set, it enables newdmd in the build.
Switch b2g.sh to sampling allocs under 4096 bytes.

This makes runninb B2G with DMD enabled /much/ faster.
DMD now takes --sample-below= instead of sample-below=.  Updating b2g.sh to match.
Merge pull request #61 from jlebar/newdmd

Add support for newdmd (bug 717853).
Only select --enable-dmd when MOZ_DMD is set.  r=me  a=bustage
Updating b2g.sh to use new DMD syntax.

DMD=1 is now equivalent to DMD="--sample-below=4093", which is what we want by default.
Bug 820203 - Add Marionette to gaia-tests.zip, r=mwu
Merge pull request #62 from jonallengriffin/bug820203

Bug 820203 - Add Marionette to gaia-tests.zip, r=mwu
Removed unused opensans font from PRODUCT_PACKAGES
Bug 821194 - Let b2g.sh recover after a failed update by renaming /system/b2g.bak - r=dhylands
Merge pull request #63 from bjacob/updater

Bug 821194 - Let b2g.sh recover after a failed update by renaming /system/b2g.bak
Bug 814579: remove out-dated desktop debug trigger
Bug 826372 - Add mozbase packages to gaia-tests.zip
Merge pull request #65 from jonallengriffin/bug826372

Bug 826372 - Add mozbase packages to gaia-tests.zip
Merge pull request #64 from vicamo/bugzilla/814579/master

Bug 814579: remove out-dated desktop debug trigger