cosmetic changes + enter behavior (#126)

* remove trailing whitespace

* always submit password on enter

Moves the keypress logic for keypresses from if-else statements
to switches, adds non-contextual behavior on pressing enter

* wrap pam actions and handle errors at on spot

* init all of text struct in input_text()

This gets rid off valgrind warning on unitialized variables

src/config.h

@@ -3,6 +3,12 @@
 
 #include "ctypes.h"
 
+enum INPUTS {
+	SESSION_SWITCH,
+	LOGIN_INPUT,
+	PASSWORD_INPUT,
+};
+
 struct lang
 {
 	char* capslock;