Added encrypted profile storage.

New profile string config option .passphrase. Can contain valid weechat
 expressions such as references to secure data storage, e.g.
 "${sec.data.}", or the environment "${env:*}". Uses
 libtoxencryptsave.so for full interoperability with other clients.

src/twc-profile.h

@@ -36,6 +36,7 @@ enum t_twc_profile_option
     TWC_PROFILE_OPTION_PROXY_TYPE,
     TWC_PROFILE_OPTION_UDP,
     TWC_PROFILE_OPTION_IPV6,
+    TWC_PROFILE_OPTION_PASSPHRASE,
 
     TWC_PROFILE_NUM_OPTIONS,
 };