Use cstdint instead of stdint.h to (hopefully) fix any problems caused by C/C++ mismatches

INT64_MIN was causing problems ('not declared'), because C99 requires some
C++-specific behavior, which C++11 prohibits...

Comments from clang's stdint implementation (http://clang.llvm.org/doxygen/stdint_8h_source.html):

	// C99 7.18.3 Limits of other integer types
	//
	//  Footnote 219, 220: C++ implementations should define these macros only when
	//  __STDC_LIMIT_MACROS is defined before <stdint.h> is included.
	//
	//  Footnote 222: C++ implementations should define these macros only when
	//  __STDC_CONSTANT_MACROS is defined before <stdint.h> is included.
	//
	// C++11 [cstdint.syn]p2:
	//
	//  The macros defined by <cstdint> are provided unconditionally. In particular,
	//  the symbols __STDC_LIMIT_MACROS and __STDC_CONSTANT_MACROS (mentioned in
	//  footnotes 219, 220, and 222 in the C standard) play no role in C++.
	//
	// C11 removed the problematic footnotes.

PixelAttributes.h

@@ -12,7 +12,7 @@
 
 #include <limits>
 #include <cmath>
-#include <stdint.h>
+#include <cstdint>
 #include <stdexcept>
 #include <cassert>
 #include "config.h"

TileGenerator.h

@@ -21,7 +21,7 @@
 #endif
 #include <set>
 #include <list>
-#include <stdint.h>
+#include <cstdint>
 #include <string>
 #include <iostream>
 #include <sstream>

ZlibDecompressor.cpp

@@ -8,7 +8,7 @@
  */
 
 #include <zlib.h>
-#include <stdint.h>
+#include <cstdint>
 #include "ZlibDecompressor.h"
 
 ZlibDecompressor::ZlibDecompressor(const unsigned char *data, std::size_t size):

db.h

@@ -1,7 +1,7 @@
 #ifndef _DB_H
 #define _DB_H
 
-#include <stdint.h>
+#include <cstdint>
 #include <vector>
 #include <string>
 #include <utility>