* Add `TransactionLike` type and `instantiateTxnIfNeeded` utility method

* Add `IntDecoding` type to TypeScript definitions

* Add lint rule to flag `module.exports` and `require` statements in TypeScript files

* Encapsulate `AlgodClient` and `IndexerClient` shared structures in an abstract class `ServiceClient`

* Abstract `ServiceClient` functionality into rewritten `HTTPClient`

* Include workaround for `algod` v1

* Include some small enhancements to abstract `JSONRequest` class

# Conflicts:
#	src/client/v2/algod/accountInformation.ts
#	src/client/v2/algod/algod.ts
#	src/client/v2/algod/block.ts
#	src/client/v2/algod/compile.ts
#	src/client/v2/algod/dryrun.ts
#	src/client/v2/algod/getApplicationByID.ts
#	src/client/v2/algod/getAssetByID.ts
#	src/client/v2/algod/pendingTransactionInformation.ts
#	src/client/v2/algod/pendingTransactions.ts
#	src/client/v2/algod/pendingTransactionsByAddress.ts
#	src/client/v2/algod/proof.ts
#	src/client/v2/algod/sendRawTransaction.ts
#	src/client/v2/algod/statusAfterBlock.ts
#	src/client/v2/algod/supply.ts
#	src/client/v2/indexer/indexer.ts
#	src/client/v2/indexer/lookupAccountByID.ts
#	src/client/v2/indexer/lookupAccountTransactions.ts
#	src/client/v2/indexer/lookupApplications.ts
#	src/client/v2/indexer/lookupAssetBalances.ts
#	src/client/v2/indexer/lookupAssetByID.ts
#	src/client/v2/indexer/lookupAssetTransactions.ts
#	src/client/v2/indexer/lookupBlock.ts
#	src/client/v2/indexer/lookupTransactionByID.ts
#	src/client/v2/indexer/searchForTransactions.ts
#	src/client/v2/jsonrequest.ts
#	src/main.ts
#	src/utils/utils.ts

ServiceClient, which includes an HTTPClient property, allows overwriting the HTTPClient instance.

This functionality is required by:
#277 (comment)

* Remove HTTPClient workaround in `src/client/algod.js`

* Add `IndexerTokenHeader` interface

* Remove extraneous IntEncoding getters/setters

… classname

* Fix `MKD` typo