I am working on porting geth to [Ubuntu Core](https://developer.ubuntu.com/en/snappy/https://developer.ubuntu.com/en/snappy/). I am testing geth on a Raspberry PI and for Ubuntu Core the $HOME directory is unique for each application. See [here](https://developer.ubuntu.com/en/snappy/guides/filesystem-layout) for more information of their filesystem layout.
For some reason in Go `usr.HomeDir` returns a different value than `$HOME` in Ubuntu Core.
Adding this at the end of `HomeDir()`
```go
fmt.Printf("at HomeDir, user.HomeDir = %s and $HOME is %s\n", usr.HomeDir, os.Getenv("HOME"))
```
gives the following output
```
at HomeDir, user.HomeDir = /home/ubuntu and $HOME is /home/ubuntu/apps/geth.sideload/IJcODREBYbHO
```
With this commit, I propose giving precedence to the `$HOME` environment variable as is also suggested by the [homedir](https://github.com/mitchellh/go-homedir/blob/master/homedir.go) project.
* xeth, rpc: implement eth_getNatSpec for tx confirmations
* rename silly docserver -> httpclient
* eth/backend: httpclient now accessible via eth.Ethereum init-d via config.DocRoot
* cmd: introduce separate CLI flag for DocRoot (defaults to homedir)
* common/path: delete unused assetpath func, separate HomeDir func
* lines with leading space are ommitted from history
* exit processed even with whitespace around
* all whitespace lines (not only empty ones) are ignored
add 7 missing commands to admin api autocomplete
registrar: methods now return proper error if reg addresses are not set. fixes#1457
rpc/console: fix personal.newAccount() regression. Now all comms accept interactive password
registrar: add registrar tests for errors
crypto: catch AES decryption error on presale wallet import + fix error msg format. fixes#1580
CLI: improve error message when starting a second instance of geth. fixes#1564
cli/accounts: unlock multiple accounts. fixes#1785
* make unlocking multiple accounts work with inline <() fd
* passwdfile now correctly read only once
* improve logs
* fix CLI help text for unlocking
fix regression with docRoot / admin API
* docRoot/jspath passed to rpc/api ParseApis, which passes onto adminApi
* docRoot field for JS console in order to pass when RPC is (re)started
* improve flag desc for jspath
common/docserver: catch http errors from response
fix rpc/api tests
common/natspec: fix end to end test (skipped because takes 8s)
registrar: fix major regression:
* deploy registrars on frontier
* register HashsReg and UrlHint in GlobalRegistrar.
* set all 3 contract addresses in code
* zero out addresses first in tests
Added a `Difference` method to `types.Transactions` which sets the
receiver to the difference of a to b (NOTE: not a **and** b).
Transaction pool subscribes to RemovedTransactionEvent adding back to
those potential missing from the chain.
When a chain re-org occurs remove any transactions that were removed
from the canonical chain during the re-org as well as the receipts that
were generated in the process.
Closes#1746
* adapt to new compiler versioning
* use compiler version as language version
* implement new solc API for versions >= 0.1.[2-9][0-9]* fixes#1770
* add optimize=1 to options
* backward compatibility (for now) for <= 0.1.1, and old versions (0.[2-9][0-9]*.[0-9]+)
* introduce compilerOptions to ContractInfo
* clean up flair, include full version string to version line and ContractInfo
* resolver -> common/registrar
* global registrar name registry interface
* add Call to resolver backend interface
* the hashReg and UrlHing contracts now initialised from global registry
* initialization of contracts uniform
* improve errors and more econsistent method names
* common/registrar/ethreg: versioned registrar
* integrate new naming and registrar in natspec
* js console api: setGlobalRegistrar, setHashReg, setUrlHint
* js test TestContract uses mining - tests fixed all pass
* eth/backend: allow PoW test mode (small ethash DAG)
* console jsre refers to resolver.abi/addr,
* cmd/geth/contracts.go moved to common/registrar
* Change password protection crypto in keystore to version 3
* Update KeyStoreTests/basic_tests.json
* Add support for PBKDF2 with HMAC-SHA256
* Change MAC and encryption key to avoid unnecessary hashing
* Add tests for test vectors in new wiki page defining version 3
* Add tests for new keystore tests in ethereum/tests repo
* Move JSON loading util to common for use in both tests and
crypto packages
* Add backwards compatibility with key store version 1
