[Qt] Fix enable/disable show and remove buttons
Remove stale and redundant src/.gitignore file

This commit removes completely the src/.gitignore file, given that the
precedent for ignoring artifacts within the `src` directory is to
add entries for them to the root .gitignore file.

Note also that the lone entry in src/.gitignore is stale anyway. As of
the switch to Autotools in 35b8af9, the build no longer build creates
artifacts in `src/test_bitcoin`. They are now written to
`src/test/test_bitcoin`, and this latter path is already ignored in the
root .gitignore file.
Merge pull request #3938

6540025 Remove stale and redundant src/.gitignore file (Chris Beams)
Merge pull request #3927

ab1edd4 [Qt] Fix enable/disable show and remove buttons (Cozz Lovan)
Fix regression tests

Taught bitcoind to close the HTTP connection after it gets a 'stop' command,
to make it easier for the regression tests to cleanly stop.
Move bitcoinrpc files to correct location.
Tidied up the python-based regression tests.
Fix test build after d138598

Building the tests was giving some vague error message about a doubly-defined
symbol.

The solution is to define ShutdownRequested in test_bitcoin.cpp as well
so that init.cpp does not get pulled in.
qt: Do proper boost::path conversion

Convert from QString unicode from/to the OS-dependent locale
as used by boost::filesystem::path as needed.

Solves #3916.
qt: Only override -datadir if different from the default

Fixes #3905.