blk: enable pool write-protection in debug mode
common: fix make clean of jemalloc

Headers generated by autotools was overwritten for both variants. After
make clean, these headers was not cleaned and therefore we had headers
from last configure run.
Merge pull request #4 from ldorau/blk-enable-pool-write-protection-in-debug-mode

blk: enable pool write-protection in debug mode
Merge pull request #3 from plebioda/fix-make-clean-jemalloc

common: fix make clean of jemalloc