This is a bug fix for the following bug (Github issue #437):
If two builds were run specifying a non-default build folder, the second
build would fail to link with duplicate symbols and may not fit on the
device. The root of this problem is that these non-default build folders
are not ignored by scan-resources, and therefore included in the build.
We fix this bug by ignoring the build directory passed into the tools.
To enable a boot-loader style application, override
"targets.bootloader_exec" or "targets.restrict_size" on a particular
target. These parameters are a bin or hex file, and an integer, in bytes,
respectively. If either override is present, then an application region
is created after the boot-loader region, when "targets.bootloader_exec"
is present, and before post-application, when "targets.restric_size" is
present. The size of the boot-loader region is read from the file
provided in the configuration.