gotwebd: kill unused id_str in got_output_repo_tree ok stsp@

gotwebd: avoid extra strdups in got_output_repo_tree ok stsp@

gotwebd: avoid extra variable in got_output_repo_tree in_repo_path was used only to build a path, it's then assigned to path (which is NULL at that point.) Just asprintf into path. ok stsp@

gotwebd: plugs leaks in got_get_repo_commits call got_get_repo_commit only once and avoid leaking the field of repo_commit at each loop iteration. ok stsp@

gotwebd: free in_repo_path in got_get_repo_commits; ok stsp@

gotwebd: always free ref in got_get_repo_commits some code-paths may leak it. ok stsp@

gotwebd: don't close tag in got_get_repo_tags too early it's still used a bit later, so defer the free'ing at the next loop iteration or at function end.

gotwebd: free commit_msg0 only at the end of got_get_repo_tags in case of a failure between when it's allocated and when it's released it might get leaked otherwise. ok and semplification stsp@

gotwebd: plug some leaks in got_get_repo_tags ok stsp@

gotwebd: free all allocated fields of repo_tag got_get_repo_tags needs some tweaking to how tag_commit is allocated too. ok stsp@

gotwebd: fix possible leaks when handling errors all very unlikely. part of a bigger diff that's ok stsp@

gotwebd: minor tweaks drop: - a tautological s[strlen(s)] == '\0' - a few duplicates checks - a lone if (error) when it's always NULL - an extra NULL check part of a bigger diff that's ok stsp@

fix dup(2) error checking in got_gotweb_openfile()

in got_operations.c, remove error variables which were only used to return NULL

get rid of (null) on the index page. ok stsp