Merge pull request #357 from dalkon/master

Player:sendTextMessage fix
Use initializer list for arrays instead of memset

... for arrays, to have them zero value initialized.
Use calloc(1, size) instead of malloc + memset.
Use numeric_limits instead of dangerous magic numbers where possible.
Major optimizations to the use of PropWriteStream

Instead of at least 1 heap allocation per item, we will re-use the
buffer and only reallocate when the stream needs to grow.