Fix usage of uninitialized variable on 32 bit architectures
Fix for "comparison is always true due to limited range of data type" errors

Seen for Fedora compilation on ARM architecture where "char" is unsigned.
Fix type narrowing conversion failures

This is seen on ppc64. Error messages like this one:
narrowing conversion of 'ecode' from 'int' to 'kXR_unt32 {aka unsigned int}' inside { }
Properly propagate offset in file block mode.
Parse block size in MB.
Implement virtual IOFileBlock::ioActive().
Simplify  Prefetch::InitiateClose() -- return ioActive state unless file is comletely downloaded or Prefetch has not been started.
Add missing offset in Prefetch::Read() when file is completely downloaded.
Add offset information in log messages.
Check all Prefetch states in IOFileBlock::ioActive.
Check file is complete in GetNextTask().
Changes in logging.
Fix instantiation of XrdSysMutexHelper.
Fix compilation error.
Change logger namespace name from XFC to XrdFileCache.
Correct plugin name in version info macro.
In configuration support k and m suffixes using XrdOuca2x::a2sz() utils.
Merge branch 'master' of https://github.com/ellert/xrootd
Update option  -bufferSize and -blockSize  

Use k and m suffixes for option -bufferSize and -blockSize.
[XrdSut] Check the length before looking inside a buffer. Fixes #126.