Resolve issues discovered by static code analysis.

Resolve issues discovered by static code analysis.

* maintMakefile: Add a rule to submit code for analysis.
* configure.ac: Check for availability of the umask() function.
* output.c (output_tmpfd, output_tmpfile): Use umask on temp files.
* makeint.h (PATH_VAR): Reserve an extra character for nul bytes.
* function.c (func_error): Initialize buffer to empty string.
* job.c (child_execute_job): Verify validity of fdin.
* main.c (main): Simplify code for makefile updating algorithm.
* arscan.c (ar_scan): Verify member name length before reading.
* read.c (readline): Cast pointer arithmetic to avoid warnings.
* remake.c (update_file): Remove unreachable code.
(name_mtime): Verify symlink name length.