CLSA-2021-1639681859 Fix CVE(s): CVE-2021-3927, CVE-2021-3928

SECURITY UPDATE: Fix heap-based buffer overflow when reading character past end of line - debian/patches/CVE-2021-3927.patch: Correct the cursor column in src/exdocmd.c. - CVE-2021-3927 SECURITY UPDATE: Fix stack-based buffer overflow when reading uninitialized memory when giving spell suggestion...