The log manager is the only one that uses the mlist_t versioned list. The
counter that keeps track of the version number was not modified using
atomic operations meaning that the compiler is free to optimize away parts
of the lock-free versioning mechanism that uses it.
To prevent this optimization, the variable is declared volatile. A rewrite
is direly needed but it cannot be done in 2.2.
The internal header directory conflicted with in-source builds causing a
build failure. This is fixed by renaming the internal header directory to
something other than maxscale.
The renaming pointed out a few problems in a couple of source files that
appeared to include internal headers when the headers were in fact public
headers.
Fixed maxctrl in-source builds by making the copying of the sources
optional.
