Merge PR #1702: lamborghini distribution & inflation spec upgrade

docs/spec/inflation/end_block.md

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+# End Block
+
+Validator provisions are minted on an hourly basis (the first block of a new
+hour). The annual target of between 7% and 20%. The long-term target ratio of
+bonded tokens to unbonded tokens is 67%.
+
+The target annual inflation rate is recalculated for each provisions cycle. The
+inflation is also subject to a rate change (positive or negative) depending on
+the distance from the target ratio (67%). The maximum rate change possible is
+defined to be 13% per year, however the annual inflation is capped as between
+7% and 20%.
+
+Within the inflation module the tokens are created, and fed to the distribution 
+module to be further processed and distributed similarly to fee distribution (with 
+the exception that there are no special rewards for the block proposer)
+
+Note that params are global params (TODO: link to the global params spec)
+
+```
+EndBlock(): 
+
+    //process provisions
+    hrsPerYr = 8766   // as defined by a julian year of 365.25 days
+    precision = 10000
+
+    time = BFTTime() // time is in seconds
+    if time > GetInflationLastTime() + 3600 
+        SetInflationLastTime(InflationLastTime + 3600)
+        inflation = nextInflation(hrsPerYr).Round(precision)
+        SetInflation(inflation)
+        
+        provisions = inflation * (pool.TotalSupply() / hrsPerYr)
+        pool.LooseTokens += provisions
+        
+        distribution.AddInflation(provisions)
+
+nextInflation(hrsPerYr rational.Rat):
+
+    bondedRatio = pool.BondedPool / pool.TotalSupply()
+
+    inflationRateChangePerYear = (1 - bondedRatio / params.GoalBonded) * params.InflationRateChange
+    inflationRateChange = inflationRateChangePerYear / hrsPerYr
+
+    inflation = GetInflation() + inflationRateChange
+    switch inflation
+        case > params.InflationMax
+            return params.InflationMax
+        case < params.InflationMin
+            return params.InflationMin
+        default 	
+            return inflation 
+```

docs/spec/inflation/state.md

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+## State
+
+### Inflation
+ - key: `0x00`
+ - value: `amino(Inflation)`
+
+The current annual inflation rate.
+
+```golang
+type Inflation sdk.Rat 
+```
+
+### InflationLastTime
+ - key: `0x01`
+ - value: `amino(InflationLastTime)`
+
+The last unix time which the inflation was processed for. 
+
+```golang
+type InflationLastTime int64
+```