Work around unfortunate libstdc++ interpretation of C++ cmath requirements

...that causes a call to std::abs with a short argument to effectively select
the double overload (via a template added with <http://gcc.gnu.org/git/
?p=gcc.git;a=commit;h=8c0edf5c2aad076cbc805299ed82845ae049f4f6>
"include/c_std/cmath (abs(_Tp)): Add"), see
<http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-toc.html#2192> "Validity and
return type of std::abs(0u) is unclear" for details.

The workaround is to use int instead of short arguments (and make sure the
integral overloads of std::abs from cstdlib are available).

Change-Id: If95363f9a54abb9cb1a57fd4828c4b91c12bc4be

svl/source/numbers/zforfind.cxx

@@ -19,7 +19,7 @@
 
 
 #include <ctype.h>
-#include <stdlib.h>
+#include <cstdlib>
 #include <float.h>
 #include <errno.h>
 #include <comphelper/string.hxx>

svl/source/numbers/zforfind.hxx

@@ -104,7 +104,7 @@ private:
     static const sal_uInt8 nMatchedUsedAsReturn;     // 0x10
 
     int    nSign;                               // Sign of number
-    short  nMonth;                              // Month (1..x) if date
+    int    nMonth;                              // Month (1..x) if date
                                                 // negative => short format
     short  nMonthPos;                           // 1 = front, 2 = middle
                                                 // 3 = end

vcl/source/edit/texteng.cxx

@@ -53,6 +53,7 @@
 
 #include <unicode/ubidi.h>
 
+#include <cstdlib>
 #include <set>
 #include <vector>
 #include <boost/foreach.hpp>
@@ -2183,7 +2184,7 @@ bool TextEngine::CreateLines( sal_uLong nPara )
         pTEParaPortion->GetLines().push_back( pL );
     }
 
-    const short nInvalidDiff = pTEParaPortion->GetInvalidDiff();
+    const int nInvalidDiff = pTEParaPortion->GetInvalidDiff();
     const sal_uInt16 nInvalidStart = pTEParaPortion->GetInvalidPosStart();
     const sal_uInt16 nInvalidEnd =  nInvalidStart + std::abs( nInvalidDiff );
     bool bQuickFormat = false;