Redefining a typedef is an error prior to C11
Fix convert.h dependencies
Move test_rename_chrs() output files out of $$opts{tmp}

Evidence of test failure evaporates if it is written to the tmp
directory (which is cleaned when the script ends), so write the files
to $$opts{path} like all the others.  Unlike the others, rename.out.tmp
is created each time in test_rename_chrs() rather than prewritten,
and is usually deleted afterwards (except when renaming tests fail).
Merge convert, filter, and rename-chrs branches

While merging, fixed merge conflicts left behind in bcftools.1,
fixed whitepace (no tabs or trailing spaces please!), reformatted
licensing boilerplate on new files to match existing files.