Update `texinfo' documentation backend inside `help' functionality:
- Add `texinfo_deleteEntrySection.sh',
`texinfo_deleteEntryChapter.sh', and
`texinfo_deleteEntryManual.sh' to separate deletion of
documentation entries based on value passed as non-option
argument to `centos-art.sh' script.
- Update `texinfo_deleteEntry' to start using
`texinfo_deleteEntrySection', `texinfo_deleteEntryChapter', and
`texinfo_deleteEntryManual'.
- Fix node construction inside `texinfo_getNode' function. Don't
remove the chapter name from node.
- Update `texinfo_updateStructureSection' to be reused in both
cases when nodes are added and removed.
- Remove chapter name from menu entries build from node. The node
value already holds the chapter name. Don't duplicate it here.
- Update replacement pattern in `texinfo_restoreCrossReferences'
and in `texinfo_deleteCrossReferences'. There is no need to use
word boundaries matching here.
- Rename `texinfo_updateChapterNode' to
`texinfo_updateChapterNodes'.