Remove several unused methods and functions

[petk]

These are not used anywhere in current pecl website repository:

• listAllwithReleases()
• listLatestReleases()
• listUpgrades()
• getByUser()
• getDateRange()
• dismissUpload()
• listAdmins()
• logintest()
• mail_pear_admins()

[petk]

Applied via 95a9d25b167dd64d071fcbaf4569ac7b1cca806b