scan-tree: Unify gitweb.* and cgit.* settings into one config option.

After some back and forth with Jamie and René, it looks like the git
config semantics are going to be like this:

- gitweb.category maps to the cgit repo config key "section"
- gitweb.description maps to the cgit repo config key "desc"
- gitweb.owner maps to the cgit repo config key "owner"
- cgit.* maps to all cgit repo config keys

This option can be enabled with "enable-git-config=1", and replaces
all previous "enable-gitweb-*" config keys.

The order of operations is as follows:

- git config settings are applied in the order that they exist in
  the git config file
- if the owner is not set from git config, get the owner using the
  usual getpwuid call
- if the description is not set from git config, look inside the
  static $path/description file
- if section-from-path=1, override whatever previous settings were
  inside of git config using the section-from-path logic
- parse $path/cgitrc for local repo.* settings, that override all
  previous settings

cgitrc.5.txt

@@ -110,24 +110,6 @@ enable-filter-overrides::
 	Flag which, when set to "1", allows all filter settings to be
 	overridden in repository-specific cgitrc files. Default value: none.
 
-enable-gitweb-desc::
-	If set to "1" and scan-path is enabled, we first check each repository
-	for the git config value "gitweb.description" to determine the owner.
-	Otherwise, the description is read from a file titled "description"
-	inside of the repository directory.
-	Default value: "1". See also: scan-path.
-
-enable-gitweb-owner::
-	If set to "1" and scan-path is enabled, we first check each repository
-	for the git config value "gitweb.owner" to determine the owner.
-	Default value: "1". See also: scan-path.
-
-enable-gitweb-section::
-	If set to "1" and scan-path is enabled, we first check each repository
-	for the git config value "gitweb.category" to determine the repository's
-	section. This value is overridden if section-from-path is enabled.
-	Default value: "1". See also: scan-path section-from-path.
-
 enable-http-clone::
 	If set to "1", cgit will act as an dumb HTTP endpoint for git clones.
 	If you use an alternate way of serving git repositories, you may wish
@@ -163,6 +145,15 @@ enable-tree-linenumbers::
 	Flag which, when set to "1", will make cgit generate linenumber links
 	for plaintext blobs printed in the tree view. Default value: "1".
 
+enable-git-config::
+	Flag which, when set to "1", will allow cgit to use git config to set
+	any repo specific settings. This option is used in conjunction with
+	"scan-path" to augment _repo._ settings. The keys gitweb.owner,
+	gitweb.category, and gitweb.description will map to the cgit keys
+	repo.owner, repo.section, and repo.desc, respectivly. All git config
+	keys that begin with "cgit." will be mapped to the corresponding "repo."
+	key in cgit. Default value: "0". See also: scan-path section-from-path.
+
 favicon::
 	Url used as link to a shortcut icon for cgit. If specified, it is
 	suggested to use the value "/favicon.ico" since certain browsers will
@@ -394,6 +385,7 @@ virtual-root::
 	NOTE: cgit has recently learned how to use PATH_INFO to achieve the
 	same kind of virtual urls, so this option will probably be deprecated.
 
+
 REPOSITORY SETTINGS
 -------------------
 repo.about-filter::