Update v0.1.15 Balance changes and bugfixes

Update v0.1.15

Towers

- Cannon Tower damage increased by 100%

- Cannon Tower projectile speed increased by 20%

Cannon will still be missing sometimes, but when it hits - it does a lot of AoE damage. Also with the projectile speed buff it feels much better. 

- Fire Tower base damage increased by 100%

- Scorched Ground damage increased from 10 per second to 15 per second, every upgrade level adds 15 damage

Upgrades 

- Right side branch was rearranged into 2 branches: Arcane Overcharge branch and Lightning Strike branch, so that Lightning Strike upgrades are not blocked by Arcane Overcharge

- Acrane Overcharge cost reduced from 3 crystals to 2 crystals

- Arcane Horizon cost reduced from 2/3/4/5/6 crystals to 1/2/3/4/5 crystals

- Greater Lightning cost reduced from 2/3/4/5/6 crystals to 1/1/2/2/3 crystals

- Scorched Ground cost reduced from 2/4/6 crystals to 1/2/3 crystals

- Frost Chains cost reduced from 2/4/6 crystals to 2/3/4 crystals

- Fireball Tower Upgrade cost reduced from 1/2/3/4/5 crystals to 1/1/1/1/1 crystal

- Frost Tower cost reduced from 1/2/3/4/5 crystals to 1/1/2/2/3 crystals

Resource Production Buildings

- Production speed of resources in Lumber Mill and Iron Mine increased by 100%: it is now 2 units of resource per active Peasant per Level of building - max level buildings with 20 peasants will produce 800 resource per minute

- Cost of Iron Mine upgrade levels changed from Iron to Wood

Players will now be able to invest excess Wood to upgrade Iron Mine levels and generate more Iron

+ A bunch of bugfixes