Merge PR #268 - add daylight savings time toggle

Adds a toggle in the preferences face that allows the user
to enable or disable the daylight savings time.

Should help produce the correct results with the sunrise/sunset presets.

A proper solution would be to integrate the tzinfo database
but it's too big for the watch at the time of this writing.
Can't be done unless it can be shrunk down into a subset
the user would be interested. Even then it's a stopgap
since the database is likely to keep growing over time.

Reviewed-by: Matheus Afonso Martins Moreira <matheus@matheusmoreira.com>
GitHub-Pull-Request: https://github.com/joeycastillo/Sensor-Watch/pull/268

movement/movement.c

@@ -185,6 +185,107 @@ const int16_t movement_timezone_offsets[] = {
     -60,    // 40 :  -1:00:00 (Azores Standard Time)
 };
 
+/* These are approximate equivalent DST timezones for each
+ * timezone in the offset table. Unlike the full tzinfo file,
+ * the time-offsets used above are incomplete, so there are
+ * cases below where an approximate DST timezone is proposed
+ * for a timezone where no one observes DST, and cases
+ * where we can't propose an equivaent DST timezone since
+ * there isn't an appropriate one in the offset table.
+ *
+ * However, this should be good enough for anyone living in
+ * a DST-observing region to manually toggle DST without
+ * having to separately change the hour and timezone info
+ * in the time set face.
+ */
+const uint8_t movement_dst_jump_table[] = {
+    1,  // 0  UTC  + 1 = CET
+    2,  // 1  CET  + 1 = SAST
+    3,  // 2  SAST + 1 = AST
+    5,  // 3  AST  + 1 = GST
+    6,  // 4  IST  + 1 = AT
+    7,  // 5  GST  + 1 = PST
+    8,  // 6  AT   + 1 = IST
+    10, // 7  PST  + 1 = KT
+    11, // 8  IST  + 1 = MT
+    9,  // 9  Nepal has no equivalent DST timezone, but they don't observe DST anyway
+    12, // 10 KT   + 1 = TST
+    11, // 11 Myanmar has no equivalent DST timezone, but they don't observe DST anyway
+    13, // 12 TST  + 1 = CST
+    15, // 13 CST  + 1 = JST
+    14, // 14 ACWST has no equivalent DST timezone, but they don't observe DST anyway
+    17, // 15 JST  + 1 = AEST
+    18, // 16 ACST + 1 = LHST
+    19, // 17 AEST + 1 = SIT
+    18, // 18 LHST has no equivalent DST timezone, but they don't observe DST anyway
+    20, // 19 SIT  + 1 = NZST
+    22, // 20 NZST + 1 = TT
+    23, // 21 CST  + 1 = CDT
+    24, // 22 TT   + 1 = LIT
+    23, // 23 CDT is already a daylight timezone
+    24, // 24 LIT has no equivalent DST timezone, but they don't observe DST anyway
+    26, // 25 BIT  + 1 = NT
+    27, // 26 NT   + 1 = HAST
+    29, // 27 HAST + 1 = AST
+    28, // 28 MIT has no equivalent DST timezone, but they don't observe DST anyway
+    30, // 29 AST  + 1 = PST
+    31, // 30 PST  + 1 = MST
+    32, // 31 MST  + 1 = CST
+    33, // 32 CST  + 1 = EST
+    35, // 33 EST  + 1 = AST
+    36, // 34 VST  + 1 = NST
+    37, // 35 AST  + 1 = BT
+    38, // 36 NST  + 1 = NDT
+    39, // 37 BT   + 1 = 39
+    38, // 38 NDT is already a daylight timezone
+    40, // 39 FNT  + 1 = AST
+    0   // 40 AST  + 1 = UTC
+};
+
+const uint8_t movement_dst_inverse_jump_table[] = {
+    40, // 0
+    0,  // 1
+    1,  // 2
+    2,  // 3
+    4,  // 4
+    3,  // 5
+    4,  // 6
+    5,  // 7
+    6,  // 8
+    9,  // 9
+    7,  // 10
+    8,  // 11
+    10, // 12
+    12, // 13
+    14, // 14
+    13, // 15
+    16, // 16
+    15, // 17
+    16, // 18
+    17, // 19
+    19, // 20
+    21, // 21
+    20, // 22
+    21, // 23
+    24, // 24
+    25, // 25
+    25, // 26
+    26, // 27
+    28, // 28
+    27, // 29
+    29, // 30
+    30, // 31
+    31, // 32
+    32, // 33
+    34, // 34
+    33, // 35
+    34, // 36
+    35, // 37
+    36, // 38
+    37, // 39
+    39  // 40
+};
+
 const char movement_valid_position_0_chars[] = " AaBbCcDdEeFGgHhIiJKLMNnOoPQrSTtUuWXYZ-='+\\/0123456789";
 const char movement_valid_position_1_chars[] = " ABCDEFHlJLNORTtUX-='01378";