Fixup reboot after install variables

* Create correctly named data manager variable 'tw_install_reboot'
* Make configurable through Settings
* Remove closing tag space in theme files (not personal preference,
  but should match surrounding code style)
* Fix the "two presses needed to enable" issue for the checkbox on the
  install screen

Change-Id: I0ceb60b4888a672e2f0ecb5672b03cc86615621a
diff --git a/variables.h b/variables.h
index 5acae75..241c7dc 100644
--- a/variables.h
+++ b/variables.h
@@ -72,7 +72,7 @@
 #define TW_SKIP_MD5_GENERATE_VAR    "tw_skip_md5_generate"
 #define TW_DISABLE_FREE_SPACE_VAR   "tw_disable_free_space"
 #define TW_SIGNED_ZIP_VERIFY_VAR    "tw_signed_zip_verify"
-#define TW_REBOOT_AFTER_FLASH_VAR   "tw_reboot_after_flash_option"
+#define TW_INSTALL_REBOOT_VAR       "tw_install_reboot"
 #define TW_TIME_ZONE_VAR            "tw_time_zone"
 #define TW_RM_RF_VAR                "tw_rm_rf"