Add tests for reading player data from a saved game

- Changed cPlayer::equip to a bitset
- Use a static constant instead of a loop to initialized player starting spells
- Only save spell points if the player has any (current if different from max)
- Symbolic forms for trait enum (and save symbolic forms also for skills)
- When loading a player, clear data which is not always present in the file
- Also add an init test for cPlayer

test/files/player/basic.txt

@@ -0,0 +1,15 @@
+UID 3
+STATUS -1 alive
+NAME "Freddy O'Hara"
+SKILL hp 20
+HEALTH 18
+EXPERIENCE 12
+SKILLPTS 3
+LEVEL 2
+STATUS web 3
+TRAIT ambidex
+TRAIT nimble
+TRAIT bad-back
+ICON 3
+RACE human
+DIRECTION e

test/files/player/skills.txt

@@ -0,0 +1,9 @@
+SKILL str 5
+SKILL dex 6
+SKILL int 3
+SKILL hp 20
+SKILL edged 3
+SKILL traps 2
+SKILL item-lore 1
+SKILL lockpick 2
+SKILL luck 1

test/files/player/spells.txt

@@ -0,0 +1,6 @@
+MAGE 3
+MAGE 7
+MAGE 20
+PRIEST 2
+PRIEST 8
+PRIEST 60