BookAddressInfo.Page singular and plural

[tdndtd]

This line “BookAddressInfo.Page” in language files should be singular if there is only one file in the folder or file opened, plural otherwise.

[Ito Mitsuhiro]

Since the text cannot be selected by number, I would like to change it to "Number of pages: {0}".

[Ito Mitsuhiro]

• BookAddressInfo.Page=Number of pages: {0} (fixed #1503)

→ <<cset a3bb32b2b7b5>>

[Ito Mitsuhiro]

Consider special handling of plurals. https://www.unicode.org/cldr/charts/44/supplemental/language_plural_rules.html

[Ito Mitsuhiro]

Argument pattern allows text to be selected. (fixed #1503)

→ <<cset fb8c9d9c31b7>>