Make caching of fProperty and fInterShowMembers thread safe

The setting of the caches held by fProperty and fInterShowMembers
can happen on different threads. Therefore the values themselves
are now atomic and appropriate locks are held when updating the values.
Take lock before calling cint

Must serialize access when getting type related information from
cint.
Added additional error reporting

While debugging a problem related to thread safety these additional
checks and error reports were very helpful.
Must take cint lock before calling TCint::CallFunc_Factory

Helgrind found that TCint::CallFunc_Factory indirectly updates
global cint state. Therefore one must take the cint lock before
calling the function. This was the only place (other than
TSelectorCint::Build) which calls this function without first
taking the lock.
Make G__FastAllocString cache thread safe

When using C++11, the cache used by G__FastAllocString utilizes
a non-locking thread safe circular buffer.
Synchronize construction of TApplication

It was possible for multiple threads to attempt construction of a
TApplication or for one thread to think the TApplication was already
constructed while another thread was in the process of doing the
construction.
Remove tabs
Auto conversion is ambiguous (at least for clang)
white space