Suspicious warnings

[mouse07410]

MacOS Sierra 10.12.6, Xcode-9.0, Macports with a lot of packages including OpenSSL-1.0.2l and gnuregex in /opt/local.

$ ./build.sh 
cmake version 3.9.4

. . . . .
/Users/uri/src/encfs/encfs/BlockFileIO.cpp:129:41: warning: comparison of integers of different
      signs: 'const size_t' (aka 'const unsigned long') and 'const int' [-Wsign-compare]
  if (partialOffset == 0 && req.dataLen <= _blockSize) {
                            ~~~~~~~~~~~ ^  ~~~~~~~~~~
/Users/uri/src/encfs/encfs/BlockFileIO.cpp:168:19: warning: comparison of integers of different
      signs: 'size_t' (aka 'unsigned long') and 'ssize_t' (aka 'long') [-Wsign-compare]
    CHECK(cpySize <= readSize);
          ~~~~~~~ ^  ~~~~~~~~
. . . . .

[benrubson]

Yes this is related to #407, compilation warnings have just been enabled.
Goal would be to correct them before 1.9.3 release 👍