#1098 Help text typos

[PeterHB]

I've copied a number of the help files from:
https://sourceforge.net/p/passwordsafe/code/HEAD/tree/trunk/pwsafe/pwsafe/help/default/html/

and corrected minor typographical errors, grammar, spelling.

The changed files:

backup_and_restore.html
change_combo.html
create_new_db.html
display_tab.html
entering_pwd.html
entering_pwd_add.html
entering_pwd_date.html
entering_pwd_pp.html
export.html
import.html
misc_tab.html
preferences.html
shortcuts_tab.html
Shortcut_Keys.html
system_tab.html

are attached as helpfiles.zip

[Rony Shapiro]

Wow - thanks for the proofreading!
Corrections gratefully reviewed, accepted and committed in 5285.