`PACKAGE_BUILDING` should probably enable `VERBOSE_BUILD` option by
default to make it easier to see which *FLAGS are used during build.
For the following builds I've put it into make.conf.
`poudriere bulk -Ctj 102amd64` logs:
- [boost-all-1.55.0](http://sprunge.us/DXgG)
- [boost-docs-1.55.0](http://sprunge.us/fFaj)
- [boost-jam-1.55.0](http://sprunge.us/IBGY)
- [boost-libs-1.55.0_8](http://sprunge.us/PhKJ)
- [boost-python-libs-1.55.0](http://sprunge.us/ACTL)
`poudriere bulk -Ctj 93i386` logs:
- [boost-all-1.55.0](http://sprunge.us/CMjM)
- [boost-docs-1.55.0](http://sprunge.us/NIae)
- [boost-jam-1.55.0](http://sprunge.us/eciK)
- [boost-libs-1.55.0_8](http://sprunge.us/UaMK)
- [boost-python-libs-1.55.0](http://sprunge.us/jPUg)
`poudriere bulk -Ctj 101i386` with some **inverted options** logs:
- [boost-all-1.55.0](http://sprunge.us/JZBj)
- [boost-docs-1.55.0](http://sprunge.us/Ybbf)
- [boost-jam-1.55.0](http://sprunge.us/SNjM)
- [boost-libs-1.55.0_8](http://sprunge.us/ReFZ)
- [boost-python-libs-1.55.0](http://sprunge.us/XiVb)