Updated copyright notices to include the year 2018.

global: Use PRI* macros and %zu instead of casting

lib-storage: mail_search_args_to_imap() - don't add parenthesis around OR There's no need to write "(OR a b)" when "OR a b" works just the same.

lib-storage: mail_search_arg_to_imap() - Fix writing invalid keywords Just write the original invalid keyword string as output. It might not be entirely invalid - just invalid within this mailbox (e.g. a mailbox doesn't allow new keywords).

lib-storage: mail_search_arg_to_imap() - minor keywords writing optimization Avoid an extra str_delete() by checking whether the parenthesis are needed.

lib-storage: mail_search_arg_to_imap() - minor FLAGS writing optimization Avoid an extra str_delete() by immediately calculating whether the parenthesis are needed.

lib-storage: mail_search_arg_to_imap() - remove () around a single flag/keyword

Partially implemented IMAP SEARCH=X-MIMEPART capability. This capability is currently Dovecot-specific.

Updated copyright notices to include the year 2017.

lib-storage: Renamed MAIL_SEARCH_ARG_FLAG_USE_TZ to _FLAG_UTC_TIMES

global: freshen copyright git ls-files | xargs perl -p -i -e 's/(\d+)-201[0-5]/$1-2016/g;s/ (201[0-5]) Dovecot/ $1-2016 Dovecot/'

lib-storage: Cleanup - separate search arg values that are set by mail_search_init()

lib-storage: Added mail_search_args_to_imap() Useful for writing IMAP SEARCH parameters from struct mail_search_arg.