expose fewer internals in packages, for easier software reuse

- prometheus is now behind an interface, they aren't dependencies for the
  reusable components anymore.
- some dependencies have been inverted: instead of packages importing a main
  package to get configuration, the main package now sets configuration in
  these packages. that means fewer internals are pulled in.
- some functions now have new parameters for values that were retrieved from
  package "mox-".

imapserver/condstore_test.go

@@ -8,7 +8,7 @@ import (
 	"github.com/mjl-/bstore"
 
 	"github.com/mjl-/mox/imapclient"
-	"github.com/mjl-/mox/moxvar"
+	"github.com/mjl-/mox/mox-"
 	"github.com/mjl-/mox/store"
 )
 
@@ -150,9 +150,9 @@ func testCondstoreQresync(t *testing.T, qresync bool) {
 		imapclient.UntaggedFetch{Seq: 6, Attrs: []imapclient.FetchAttr{imapclient.FetchUID(6), noflags, imapclient.FetchModSeq(clientModseq + 4)}},
 	)
 
-	moxvar.Pedantic = true
+	mox.SetPedantic(true)
 	tc.transactf("bad", `Fetch 1 Flags (Changedsince 0)`) // 0 not allowed in syntax.
-	moxvar.Pedantic = false
+	mox.SetPedantic(false)
 	tc.transactf("ok", "Uid fetch 1 (Flags) (Changedsince 0)")
 	tc.xuntagged(imapclient.UntaggedFetch{Seq: 1, Attrs: []imapclient.FetchAttr{imapclient.FetchUID(1), noflags, imapclient.FetchModSeq(clientModseq)}})
 

imapserver/fetch.go

@@ -17,8 +17,8 @@ import (
 	"github.com/mjl-/bstore"
 
 	"github.com/mjl-/mox/message"
+	"github.com/mjl-/mox/mox-"
 	"github.com/mjl-/mox/moxio"
-	"github.com/mjl-/mox/moxvar"
 	"github.com/mjl-/mox/store"
 )
 
@@ -102,7 +102,7 @@ func (c *conn) cmdxFetch(isUID bool, tag, cmdstr string, p *parser) {
 				p.xspace()
 				changedSince = p.xnumber64()
 				// workaround: ios mail (16.5.1) was seen sending changedSince 0 on an existing account that got condstore enabled.
-				if changedSince == 0 && moxvar.Pedantic {
+				if changedSince == 0 && mox.Pedantic {
 					// ../rfc/7162:2551
 					xsyntaxErrorf("changedsince modseq must be > 0")
 				}

imapserver/server.go

@@ -1456,7 +1456,7 @@ func (c *conn) cmdStarttls(tag, cmd string, p *parser) {
 		panic(fmt.Errorf("starttls handshake: %s (%w)", err, errIO))
 	}
 	cancel()
-	tlsversion, ciphersuite := mox.TLSInfo(tlsConn)
+	tlsversion, ciphersuite := moxio.TLSInfo(tlsConn)
 	c.log.Debug("tls server handshake done", slog.String("tls", tlsversion), slog.String("ciphersuite", ciphersuite))
 
 	c.conn = tlsConn