changed plugin library types from SHARED to MODULE

Fixed float/double/decimal converion for prepared statements:
  since _gcvt (Windows) and gcvt (*nix) deliver different results
  we use now dtoa.c from server package, which is licensed under
  LGPL.

include/ma_string.h

@@ -23,6 +23,14 @@
 
 #include <string.h>
 
+typedef enum {
+  MY_GCVT_ARG_FLOAT,
+  MY_GCVT_ARG_DOUBLE
+} my_gcvt_arg_type;
+
+size_t ma_fcvt(double x, int precision, char *to, my_bool *error);
+size_t ma_gcvt(double x, my_gcvt_arg_type type, int width, char *to,
+               my_bool *error);
 char *ma_ll2str(long long val,char *dst, int radix);
 
 #endif