Revert "Allow Python 3."

This reverts commit 7c66577671.

src/api.py

@@ -58,7 +58,11 @@ For further examples please reference `.tests.test_api`.
 """
 
 import base64
-import ConfigParser
+try:
+	import ConfigParser
+except ModuleNotFoundError:
+	import configparser as ConfigParser
+	ConfigParser.SafeConfigParser = ConfigParser.ConfigParser
 import errno
 import hashlib
 import httplib

src/bitmessagecurses/__init__.py

@@ -10,7 +10,11 @@ Bitmessage commandline interface
 #     * python2-pythondialog
 #  * dialog
 
-import ConfigParser
+try:
+	import ConfigParser
+except ModuleNotFoundError:
+	import configparser as ConfigParser
+	ConfigParser.SafeConfigParser = ConfigParser.ConfigParser
 import curses
 import os
 import sys

src/bmconfigparser.py

@@ -2,7 +2,11 @@
 BMConfigParser class definition and default configuration settings
 """
 
-import ConfigParser
+try:
+	import ConfigParser
+except ModuleNotFoundError:
+	import configparser as ConfigParser
+	ConfigParser.SafeConfigParser = ConfigParser.ConfigParser
 import os
 import shutil
 from datetime import datetime
@@ -60,21 +64,33 @@ class BMConfigParser(ConfigParser.SafeConfigParser):
             raise ValueError("Invalid value %s" % value)
         return ConfigParser.ConfigParser.set(self, section, option, value)
 
-    def get(self, section, option, raw=False, variables=None):
+    def get(self, section, option, raw=False, vars=None, fallback=None):
         # pylint: disable=arguments-differ
         try:
             if section == "bitmessagesettings" and option == "timeformat":
-                return ConfigParser.ConfigParser.get(
+                try:
-                    self, section, option, raw, variables)
+                    return ConfigParser.ConfigParser.get(
+                        self, section, option, raw=raw, vars=vars, fallback=fallback)
+                except TypeError:
+                    return ConfigParser.ConfigParser.get(
+                        self, section, option, raw=raw, vars=vars)
             try:
                 return self._temp[section][option]
             except KeyError:
                 pass
-            return ConfigParser.ConfigParser.get(
+            try:
-                self, section, option, True, variables)
+	            return ConfigParser.ConfigParser.get(
+                    self, section, option, raw=True, vars=vars, fallback=fallback)
+            except TypeError:
+	            return ConfigParser.ConfigParser.get(
+                    self, section, option, raw=True, vars=vars)
         except ConfigParser.InterpolationError:
-            return ConfigParser.ConfigParser.get(
+            try:
-                self, section, option, True, variables)
+                return ConfigParser.ConfigParser.get(
+                    self, section, option, raw=True, vars=vars, fallback=fallback)
+            except TypeError:
+                return ConfigParser.ConfigParser.get(
+                    self, section, option, raw=True, vars=vars)
         except (ConfigParser.NoSectionError, ConfigParser.NoOptionError) as e:
             try:
                 return BMConfigDefaults[section][option]

src/debug.py

@@ -35,7 +35,11 @@ Logging is thread-safe so you don't have to worry about locks,
 just import and log.
 """
 
-import ConfigParser
+try:
+	import ConfigParser
+except ModuleNotFoundError:
+	import configparser as ConfigParser
+	ConfigParser.SafeConfigParser = ConfigParser.ConfigParser
 import logging
 import logging.config
 import os

src/depends.py

@@ -301,7 +301,7 @@ def check_openssl():
                 ' OpenSSL 0.9.8b or later with AES, Elliptic Curves (EC),'
                 ' ECDH, and ECDSA enabled.')
             return False
-        matches = cflags_regex.findall(openssl_cflags)
+        matches = cflags_regex.findall(openssl_cflags.decode())
         if matches:
             logger.error(
                 'This OpenSSL library is missing the following required'