Fix typos and allow Measurement to use only the Measure name. (#61)

* Fix typos and allow Measurement to use only the Measure name.

* Fix some comments.

Author: Bogdan Drutu

stats/DataAggregation.md

@@ -31,7 +31,7 @@ within the library.
 * `columns`: an array of tag keys. These values associated with tags of this name form the basis 
 by which individual stats will be aggregated (one aggregation per unique tag value). If none are 
 provided, then all data is recorded in a single aggregation.
-* `aggregation`: `Distribution`, `Count`, `Sum`, `Mean`.
+* `aggregation`: `Distribution`, `Count`, `Sum`, `LastValue`, `Max`.
 
 Implementations SHOULD define a View data type, constructed from the parameters above. Views MAY 
 have getters for retrieving all of the information used in View definition. Once created, View 

stats/Record.md

@@ -13,7 +13,7 @@ A Measure describes a value with the following metadata:
 * `name`: a string by which the measure will be referred to, e.g. "rpc_server_latency", or
 "vm_cpu_cycles". Names MUST be unique within the library. It is recommended to use names 
 compatible with the intended end usage, e.g, use host/path pattern.
-* `description`: a string describes the measure, e.g. "RPC latency in seconds", "Virtual cycles
+* `description`: a string describing the measure, e.g. "RPC latency in seconds", "Virtual cycles
 executed on VM".
 * `unit`: a string describing the unit used for the `Measure`. Follows the format described by
 [Unified Code for Units of Measure](http://unitsofmeasure.org/ucum.html).
@@ -33,12 +33,13 @@ References to Measures in the system MAY be obtained from querying of registered
 functionality is required to decouple the recording of the data from the exporting of the data.
 
 For languages that do not allow private properties/metadata and if they are needed implementations 
-MAY define a `MeasureDescription` data type which contains all the read-only fields  from the 
+MAY define a `MeasureDescription` data type which contains all the read-only fields from the
 `Measure` definition such as: `name`, `description`, `unit` and `type`.
 
 ## Measurement
 A `Measurement` is defined from the following:
-* `Measure`: the `Measure` to which this `value` is applied.
+* `Measure`: the `Measure` to which this `value` is applied. Some implementations may use the
+measure name instead of the `Measure`.
 * `value`: recorded value, MUST have the appropriate type to match the `Measure` definition.
 
 Implementations MAY define a `MeasurementMap` which describes a set of data points to be collected