Specify field widths for scanf to prevent potential crashes.

[Quipyowert2]

This patch adds field widths to scanf() calls in four C source files to prevent potential crashes that Cppcheck warns about.

Here are the warnings Cppcheck gives about scanf()/sscanf()/fscanf():

[contrib\curve.c:203]: (warning) scanf() without field width limits can crash with huge input data.
[contrib\curve.c:227]: (warning) scanf() without field width limits can crash with huge input data.
[contrib\curve.c:387]: (warning) fscanf() without field width limits can crash with huge input data.
[contrib\curve.c:535]: (warning) scanf() without field width limits can crash with huge input data.
[putt\hole.c:75]: (warning) sscanf() without field width limits can crash with huge input data.
[share\mapc.c:795]: (warning) sscanf() without field width limits can crash with huge input data.
[share\mapc.c:939]: (warning) sscanf() without field width limits can crash with huge input data.
[share\solid_base.c:907]: (warning) sscanf() without field width limits can crash with huge input data.

[Quipyowert2]

Rebased onto master and fixed the merge conflict.