simmer 3.8.0

New features:

• New data source add_dataframe enables the attachment of precomputed data, in the form of a data frame, to a trajectory. It can be used instead of (or along with) add_generator. The most notable advantage over the latter is that add_dataframe is able to automatically set attributes and prioritisation values per arrival based on columns of the provided data frame (#140 closing #123).
• New set_source activity deprecates set_distribution(). It works both for generators and data sources (275a09c, as part of #140).
• New monitoring interface allows for disk offloading. The simmer() constructor gains a new argument mon to provide different types of monitors. By default, monitoring is performed in-memory, as usual. Additionally, monitoring can be offloaded to disk through monitor_delim and monitor_csv, which produce flat delimited files. But more importantly, the C++ interface has been refactorised to enable the development of new monitoring backends (#146 closing #119).

Minor changes and fixes:

• Some documentation improvements (1e14ed7, 194ed05).
• New default until=Inf for the run method (3e6aae9, as part of #140).
• branch and clone now accept lists of trajectories, in the same way as join, so that there is no need to use do.call (#142).
• The argument continue (present in seize and branch) is recycled if only one value is provided but several sub-trajectories are defined (#143).
• Fix process reset: sources are reset in strict order of creation (e7d909b).
• Fix infinite timeouts (#144).