Notification of string changes

Author: Daniel Ziegenberg
MDL-73700 core: remove unused functions and strings from installer
While searching for no longer needed PHP 5.x & 7.0 checks, the
`phpversionhelp` lang string and, subsequently, the `memorylimithelp`
lang string and the `install_helpbutton()` and
`install_print_help_page()` functions were discovered. According to
comments on MDL-2787 and MDL-64482 they are no longer in use since
Moodle 1.x (approximately), neither reachable since some good versions
ago. With MDL-17458 (commit 3b09331066a91c51a2de1676ca8179ca7c90f64b),
the function `print_compatibility_row()` was gone, and it seems like it
was the only place calling `install_helpbutton()`. And
`install_helpbutton()` was the only place where a link to the help mode
(e.g. `install.php?help=$helpfield`) ever surfaced. As both lang
strings and functions are particular to the installer and never could
have been used outside of it, we are going for direct deletion instead
of regular deprecation.

Signed-off-by: Daniel Ziegenberg <daniel@ziegenberg.at>


http://git.moodle.org/gw?p=moodle.git;a=commit;h=39fda04cdcd82c8f56b50c34c40e35f29bcbf868
http://github.com/moodle/moodle/commit/39fda04cdcd82c8f56b50c34c40e35f29bcbf868

- 5.0 en [memorylimithelp,core_install]
- 5.0 en [phpversionhelp,core_install]